Silverman's game: Difference between revisions

From formulasearchengine
Jump to navigation Jump to search
en>David Eppstein
rm redundant stub tag
 
Remove irrelevant constraint
Line 1: Line 1:
Not many individսals follow-through on their desire to еat nutritiouslү and beсome far healthier. This post will supply several tips on [http://techtrainsoft.com/node/20096 vigrx plus how long does it take to work] to make sensible eaѕy adјustmentѕ in yoսr lifetime.<br><br>
{{lowercase}}
\ոDon't depгive on your own of ƴour beloved foods entiгely, but replaϲe far healthier renditiοns whenever possible. Leaгn which meals arе healthful by understanding thеir nutritiօus info. This task Һas become manufactured much eaѕier in recent times, with so many eatіng places offerіng nutrients informаtion aboսt theіr solutions.<br><br>A multiple-supplement is definitely а significant aԁdition to your diet proɡram. This can bе effective since, whilst it's a lot better to acquire your nutritional vitamins from natural meals ѕouгces, having the 'insurance' of your mսlti-vitamin supplement ѕignifies that, if for reasons unknown at sоme time you don't get an ample amount of some vitamin from the standard diet, you're nonetheless protected.<br><br>Do you quite not take in so much steak? Instead of possessing it as bеing a main meаl, apply it as a garnish. One way to utilіse it really is tо improνe the feel and flavor of foodѕ from otheг food groups, which includes greens аnd աhole grains. China and Mediterraneаn ethnicitieѕ do that. Research indіcatеs that, normally, they may have less incidences of cοronary disease.<br><br>When proceeding searching for houѕehold goods, enable your youngstеrs to assist yoս in selecting food proɗuctѕ. Permit them to choose the vеgetables and fruit, so that they will try to eat them rather than leaving Ƅehind them around the platter. Youngsters migɦt even want to try out something totally new, like sρarkling and bright food items that get their consideration.<br><br>Ginger herb is a great way to treat movement illness. Ginger handily can be purchased in simple to swallow pills. Getting 1,000mg of ginger herb an hour before Ԁeparting and for each about three several hours next is ideal. Ginger is perfect for protecting against the ƅelly cramps and nausea usually related with traveling. Gingeг teas ɑnd candies can [http://Escortmaltepe.net/author/flvbw/ Vigrx plus gel] also be extremely helpful.<br><br>Improve your diet program with a normal nutrіent geneгallƴ known as inulin. Inulin is really a product located in foods like leeks, garlic, ɑnd artichokes. Ԝhilst you may have been traіned thаt carbohydrates are poor, this helps you shed weigҺt and calms your digestiߋn. Additionally, garlic clove helps develop immunity. If you're reluctant you'll ǥet garlic clove Ьreath, it is possible to blanch the gaгlic to reԁuce the ѕmell.<br><br>The ideal way to cook meats from a healthy standpoint are preparing, broiling, grilling, and roasting. Staгt using food preparation squiгt ratҺer thаn butter while preparing foods. Any time you light brown meat, be sure to tension and wash wіth very hot water. It will help eliminate the extra fat in yοur beef.<br><br>All too numerous reduced-fat food items compensate for the flavorful extra fat these are absent with additіonal glucose or ѕugar substіtutеs. Observe the еlements listing of food items publicized as low in calories simply because there might be pοor artificial [http://search.un.org/search?ie=utf8&site=un_org&output=xml_no_dtd&client=UN_Website_en&num=10&lr=lang_en&proxystylesheet=UN_Website_en&oe=utf8&q=additives&Submit=Go additives] that are utilizeɗ to retain the meals from flavorful dull.<br><br>Make sure you're getting еnough relaxation and enjоying a lot leѕs alcohol each ɑnd every day. Alcohol boosts essentіal oil creation on your own encounter and enlarǥes your pores. Huge pores let extra dirt and contamination wіthin, resulting in acne. Intention for around several hoսгs of sleepіng every night and mɑintain your liquor ɑbsorption less than two drinks.<br><br>So that it is a indicate find out new recipes iѕ a terrific way to ensure seem nutгients and correct behаvior. Seeking new dishes can keep your diet іntriquing, notable and difficult. It iѕ an outstanding means of making healthful having еnjoyable and an еxperіence instead of [http://www.wonderhowto.com/search/perfunctory/ perfunctory] and dull.<br><br>[http://Geswindt.co.za/forum/vigrx-plus-kaskus-total-wellness-stick-these-convenient-diet-suggestions Vigrx plus does not work] Remember to keep a good supply of frozen fresh vegetables with youг freeƶer which means you will invariably incorpoгate sߋme to make use of. Yoս aгe able to worƙ these into most foods, as edges, ѕtir  [http://www.playmylist.fr/groups/vigrx-plus-dosage-instructions-follow-these-simple-guidelines-to-improve-you-nourishment/ Vigrx plus jakarta] fry or աith poultry and meat mеals. Ϝreezing your healthy dinner is extremely-handy, so you won't have bad meals to be concerned аbout.<br><br>Let yourself to cheat a couple of tіmes eaсh month. This equally maintains you going insane, and it likewise ԝill give yoս a chance to ɦаve a еnjoyable sociаl life. Ԝith regards to your aunt's party, you will need to observe with some bіrthday сelebrɑtion biгthday cakе and wines.<br><br>Shop smartly when searсhing for whole grain products. Even tҺough it looks healthy and is also the correct shade, this may not reveal Һigh quɑlity. Whetɦer or not the brand says "100 percent wheat or grain," that doesn't implү that it is completely wholegrain. To get to the bottom of the entirе grain issue, check out the personal cߋmponents.<br><br>Get more health proteins by [http://Search.un.org/search?ie=utf8&site=un_org&output=xml_no_dtd&client=UN_Website_en&num=10&lr=lang_en&proxystylesheet=UN_Website_en&oe=utf8&q=consuming&Submit=Go consuming] much less meat and more beans and legumes. Black color legumes in Cubаn food are fantastic, and you can change bеef in tacos witɦ lentils and seasonings. You can utіlize legumes in soupѕ, burritos, tacos along wіth other things to enhance fiber content material without resorting to bеef.<br><br>Instгuct your kids how to buy foօd in the food maгket. Prove to them merchandise tags so tɦey can take notice of poor food choices and toned fɑr more towards greater diet.<br><br>Get substitutes for tοp-extra fat dairy foods. Swapping milk products which arе riсh in body fat with reduсed-body fat suЬstitutes will greatly increase the healtҺiness of yοսr diet program. Alternative simple fɑt free yogurt for sour skіn cream in dips. Try using evaporated milk which is body fat cost-free for cream. Alternative pгoduct cheeses for ricotta daiгy products. You can make these substitսtiоns but stіll taҡe pleasure in delіcious meаls that include dairy products.<br><br>So, if you would like inspire your household to consume greater and direct by case in point, the ideas within this report may help you! You will lеarn good nutrients will be a practice that keeps you wholesome and pleaseɗ.
{{Electronic structure methods}}
In [[solid-state physics]], '''k·p [[perturbation theory (quantum mechanics)|perturbation theory]]''' is an approximation scheme for calculating the [[band structure]] (particularly [[Effective mass (solid-state physics)|effective mass]]) and optical properties of crystalline solids.<ref name=Yu2.6/><ref name=Kittel/><ref name=Harrison>
{{cite book
|author=W.P. Harrison
|year=1989 |origyear=1980
|title=Electronic Structure and the Properties of Solids
|edition=Reprint
|pages=158 ''ff''
|publisher=[[Dover Publications]]
|isbn=0-486-66021-4
}}</ref> It is pronounced "k dot p", and is also called the "k·p method". This theory has been applied specifically in the framework of the '''Luttinger–Kohn''' model (after [[Joaquin Mazdak Luttinger]] and [[Walter Kohn]]), and of the '''Kane model''' (after [[Evan O. Kane]]).
 
==Background and derivation==
 
===Bloch's theorem and wavevectors===
{{see also|Bloch wave}}
 
According to [[quantum mechanics]] (in the [[Hartree-Fock|single-electron approximation]]), the [[electron]]s in any material have [[wavefunction]]s which can be described by the following [[Schrödinger equation]]:
:<math>\left(\frac{p^2}{2m}+V\right)\psi = E\psi</math>
where '''p''' is the [[momentum operator|quantum-mechanical momentum operator]], ''V'' is the [[electrostatic potential|potential]], and ''m'' is the mass of an electron. (This equation neglects the [[spin-orbit effect]]; see below.)
 
In a [[crystalline solid]], ''V'' is a [[periodic function]], with the same periodicity as the [[crystal lattice]]. [[Bloch wave|Bloch's theorem]] proves that the solutions to this differential equation can be written as follows:
:<math>\psi_{n,\mathbf{k}}(\mathbf{x}) = e^{i\mathbf{k}\cdot\mathbf{x}} u_{n,\mathbf{k}}(\mathbf{x})</math>
where '''k''' is a vector (called the ''wavevector''), ''n'' is a discrete index (called the ''[[band structure|band]] index''), and ''u''<sub>''n'','''k'''</sub> is a function with the same periodicity as the crystal lattice.
 
For any given ''n'', the associated states are called a [[band structure|band]]. In each band, there will be a relation between the wavevector '''k''' and the energy of the state ''E''<sub>''n'','''k'''</sub>, called the [[dispersion relation|band dispersion]]. Calculating this dispersion is one of the primary applications of ''k''·''p'' perturbation theory.
 
===Perturbation theory===
{{see also|Perturbation theory (quantum mechanics)}}
 
The periodic function ''u''<sub>''n'','''k'''</sub> satisfies the following Schrödinger-type equation:<ref name=Yu2.6>
{{cite book
|author=P. Yu, M. Cardona
|year=2005
|title=Fundamentals of Semiconductors: Physics and Materials Properties
  |url=http://books.google.com/books?id=W9pdJZoAeyEC&pg=PA244&dq=isbn=3540254706#PPA68,M1
|edition=3rd
|page=Section 2.6, pp. 68 ''ff' |nopp=yes
|publisher=[[Springer (publisher)|Springer]]
|isbn=3-540-25470-6
}}</ref>
:<math>H_{\mathbf{k}} u_{n,\mathbf{k}}=E_{n,\mathbf{k}}u_{n,\mathbf{k}}</math>
where the [[Hamiltonian (quantum mechanics)|Hamiltonian]] is
:<math>H_{\mathbf{k}} = \frac{p^2}{2m} + \frac{\hbar \mathbf{k}\cdot\mathbf{p}}{m} + \frac{\hbar^2 k^2}{2m}  + V </math>
Note that '''k''' is a vector consisting of three real numbers with units of [[inverse length]], while '''p''' is a vector of operators; to be explicit,
:<math>\mathbf{k}\cdot\mathbf{p} = k_x (-i\hbar \frac{\partial}{\partial x}) + k_y (-i\hbar \frac{\partial}{\partial y}) + k_z (-i\hbar \frac{\partial}{\partial z})</math>
In any case, we write this Hamiltonian as the sum of two terms:
:<math>H=H_0+H_{\mathbf{k}}', \;\; H_0 = \frac{p^2}{2m}+V, \;\; H_{\mathbf{k}}' = \frac{\hbar^2 k^2}{2m} + \frac{\hbar \mathbf{k}\cdot\mathbf{p}}{m}</math>
This expression is the basis for [[perturbation theory (quantum mechanics)|perturbation theory]]. The "unperturbed Hamiltonian" is ''H''<sub>0</sub>, which in fact equals the exact Hamiltonian at '''k'''=0 (i.e., at the [[Gamma point]]). The "perturbation" is the term <math>H_{\mathbf{k}}'</math>. The analysis that results is called "k·p perturbation theory", due to the term proportional to ''k''·''p''. The result of this analysis is an expression for ''E''<sub>''n'','''k'''</sub> and ''u''<sub>''n'','''k'''</sub> in terms of the energies and wavefunctions at '''k'''=0.
 
Note that the "perturbation" term <math>H_{\mathbf{k}}'</math> gets progressively smaller as '''k''' approaches zero. Therefore, k·p perturbation theory is most accurate for small values of '''k'''. However, if enough terms are included in the [[perturbation theory (quantum mechanics)|perturbative expansion]], then the theory can in fact be reasonably accurate for any value of '''k''' in the entire [[Brillouin zone]].
 
===Expression for a nondegenerate band===
 
For a nondegenerate band (i.e., a band which has a different energy at '''k'''=0 from any other band), with an [[extremum]] at '''k'''=0, and with no [[spin-orbit coupling]], the result of ''k''·''p'' perturbation theory is (to [[perturbation theory|lowest nontrivial order]]):<ref name=Yu2.6/>
:<math>u_{n,\mathbf{k}} = u_{n,0}+\frac{\hbar}{m}\sum_{n' \neq n}\frac{\langle u_{n,0} | \mathbf{k}\cdot\mathbf{p} | u_{n',0} \rangle}{E_{n,0}-E_{n',0}} u_{n',0}</math>
:<math>E_{n,\mathbf{k}} = E_{n,0}+\frac{\hbar^2 k^2}{2m} + \frac{\hbar^2}{m^2} \sum_{n'\neq n} \frac{|\langle u_{n,0} | \mathbf{k}\cdot\mathbf{p} | u_{n',0} \rangle |^2}{E_{n,0}-E_{n',0}}</math>
 
The parameters that are required to do these calculations, namely ''E''<sub>''n'',0</sub> and <math>\langle u_{n,0} | \mathbf{p} | u_{n',0} \rangle</math>, are typically inferred from experimental data. (The latter are called "optical matrix elements".)
 
In practice, the sum over ''n''' often includes only the nearest one or two bands, since these tend to be the most important (due to the denominator). However, for improved accuracy, especially at larger '''k''', more bands must be included, as well as more terms in the perturbative expansion than the ones written above.
 
====Effective mass====
{{main|Effective mass (solid-state physics)}}
 
Using the expression above for the energy dispersion relation, a simplified expression for the effective mass in the conduction band of a semiconductor can be found.<ref name=Harrison/> To approximate the dispersion relation in the case of the conduction band, take the energy ''E<sub>n0</sub>'' as the minimum conduction band energy ''E<sub>c0</sub>'' and include in the summation only terms with energies near the valence band maximum, where the energy difference in the denominator is smallest. (These terms are the largest contributions to the summation.) This denominator is then approximated as the band gap ''E<sub>g</sub>'', leading to an energy expression:
:<math>E_c(\boldsymbol k ) \approx E_{c0} +\frac{(\hbar k)^2}{2m} +\frac{\hbar ^2}{{E_g}m^2}\sum_n  {|\langle u_{c,0}|\mathbf{k}\cdot\mathbf{p}| u_{n,0} \rangle |^2}  </math>
The effective mass in direction ℓ is then:
:<math> \frac{1} {m}_{\ell} = {{1} \over {\hbar^2}} \sum_{ m} \cdot {{\partial^{\ 2} E_{c} (\boldsymbol{k})} \over {\partial k_{\ell} \partial k_ m}} \approx \frac{1}{m}+\frac{2}{E_gm^2}\sum_{m,\ n} {\langle u_{c,0}|p_{\ell}| u_{n,0} \rangle }{\langle u_{n,0}|p_{m}| u_{c,0} \rangle }  </math>
Ignoring the details of the matrix elements, the key consequences are that the effective mass varies with the smallest bandgap and goes to zero as the gap goes to zero.<ref name=Harrison/> A useful approximation for the matrix elements in [[direct gap]] semiconductors is:<ref name=DirectGap>A ''direct gap'' semiconductor is one where the valence band maximum and conduction band minimum occur at the same position in '''k'''-space, usually the so-called Γ-point where '''k''' = 0.</ref>  
:<math>\frac{2}{E_gm^2}\sum_{m,\ n} {|\langle u_{c,0}|p_{\ell}| u_{n,0} \rangle |}{|\langle u_{c,0}|p_{m}| u_{n,0} \rangle |} \approx 20\mathrm{eV} \frac{1}{mE_{g}} \ , </math>
which applies within about 15% or better to most group-IV, III-V and II-VI semiconductors.<ref name=Table2.22>See [http://books.google.com/books?id=W9pdJZoAeyEC&pg=PA244&dq=isbn:3540254706#PPA71,M1 Table 2.22] in Yu & Cardona, ''op. cit.''</ref>
 
In contrast to this simple approximation, in the case of valence band energy the ''spin-orbit'' interaction must be introduced (see below) and many more bands must be individually considered. The calculation is provided in Yu and Cardona.<ref name=valence>See Yu & Cardona, ''op. cit.'' pp. 75-82</ref> In the valence band the mobile carriers are ''[[Electron hole|holes]]''. One finds there are two types of hole, named ''heavy'' and ''light'', with anisotropic masses.
 
===''k''·''p'' model with spin-orbit interaction===
 
Including the [[spin-orbit interaction]], the Schrödinger equation for ''u'' is:<ref name=Kittel>
{{cite book
|author=C. Kittel
|year=1987
|title=Quantum Theory of Solids
|edition=Second Revised Printing
|pages=186–190
|isbn=0-471-62412-8
|publisher=[[John Wiley & Sons|Wiley]]
|location=New York
}}</ref>
:<math>H_{\mathbf{k}} u_{n,\mathbf{k}}=E_{n,\mathbf{k}}u_{n,\mathbf{k}}</math>
where
:<math>H_{\mathbf{k}} = \frac{p^2}{2m} + \frac{\hbar \mathbf{k}\cdot\mathbf{p}}{m} + \frac{\hbar^2 k^2}{2m}  + V + \frac{1}{4 m^2 c^2} (\vec \sigma \times \nabla V)\cdot (\hbar\mathbf{k}+\mathbf{p})</math>
where <math>\vec \sigma=(\sigma_x,\sigma_y,\sigma_z)</math> is a vector consisting of the three [[Pauli matrix|Pauli matrices]]. This Hamiltonian can be subjected to the same sort of perturbation-theory analysis as above.
 
===Calculation in degenerate case===
 
For degenerate or nearly degenerate bands, in particular the [[valence band]]s in certain materials such as [[gallium arsenide]], the equations can be analyzed by the methods of [[perturbation theory (quantum mechanics)|degenerate perturbation theory]].<ref name=Yu2.6/><ref name=Kittel/> Models of this type include the "[[Luttinger-Kohn model]]" (a.k.a. "Kohn-Luttinger model"),<ref>
{{cite journal
|author=J. M. Luttinger, W. Kohn
|year=1955
|title=Motion of Electrons and Holes in Perturbed Periodic Fields
|journal=[[Physical Review]]
|volume=97 |issue= |pages=869
|doi=10.1103/PhysRev.97.869
|bibcode = 1955PhRv...97..869L }}</ref> and the "[[Kane model]]".<ref>
{{cite journal
|author=Evan O. Kane
|year=1957
|title=Band Structure of Indium Antimonide
|journal=[[Journal of Physics and Chemistry of Solids]]
|volume=1 |pages=249
|doi=10.1016/0022-3697(57)90013-6
|bibcode = 1957JPCS....1..249K }}</ref>
 
==Notes and references==
{{reflist}}
 
==See also==
{{Col-begin}}
{{Col-1-of-2}}
'''Electronic band structure'''
* [[Electronic band structure]]
* [[Nearly free electron model]]
* [[Kronig-Penney model]]
'''Band properties'''
* [[Band gap]]
* [[Effective mass (solid-state physics)|Effective mass]]
* [[Density of states]]
* [[Fermi surface]]
{{Col-2-of-2}}
'''Wavefunctions'''
* [[Wannier functions]]
* [[Bloch waves]]
'''Fundamental theory'''
* [[Kohn-Sham equations]]
* [[Local-density approximation]]
 
{{col-end}}
 
{{DEFAULTSORT:K P Perturbation Theory}}
[[Category:Electronic structure methods]]

Revision as of 14:27, 24 December 2013

Template:Lowercase Template:Electronic structure methods In solid-state physics, k·p perturbation theory is an approximation scheme for calculating the band structure (particularly effective mass) and optical properties of crystalline solids.[1][2][3] It is pronounced "k dot p", and is also called the "k·p method". This theory has been applied specifically in the framework of the Luttinger–Kohn model (after Joaquin Mazdak Luttinger and Walter Kohn), and of the Kane model (after Evan O. Kane).

Background and derivation

Bloch's theorem and wavevectors

DTZ's public sale group in Singapore auctions all forms of residential, workplace and retail properties, outlets, homes, lodges, boarding homes, industrial buildings and development websites. Auctions are at present held as soon as a month.

We will not only get you a property at a rock-backside price but also in an space that you've got longed for. You simply must chill out back after giving us the accountability. We will assure you 100% satisfaction. Since we now have been working in the Singapore actual property market for a very long time, we know the place you may get the best property at the right price. You will also be extremely benefited by choosing us, as we may even let you know about the precise time to invest in the Singapore actual property market.

The Hexacube is offering new ec launch singapore business property for sale Singapore investors want to contemplate. Residents of the realm will likely appreciate that they'll customize the business area that they wish to purchase as properly. This venture represents one of the crucial expansive buildings offered in Singapore up to now. Many investors will possible want to try how they will customise the property that they do determine to buy by means of here. This location has offered folks the prospect that they should understand extra about how this course of can work as well.

Singapore has been beckoning to traders ever since the value of properties in Singapore started sky rocketing just a few years again. Many businesses have their places of work in Singapore and prefer to own their own workplace area within the country once they decide to have a everlasting office. Rentals in Singapore in the corporate sector can make sense for some time until a business has discovered a agency footing. Finding Commercial Property Singapore takes a variety of time and effort but might be very rewarding in the long term.

is changing into a rising pattern among Singaporeans as the standard of living is increasing over time and more Singaporeans have abundance of capital to invest on properties. Investing in the personal properties in Singapore I would like to applaud you for arising with such a book which covers the secrets and techniques and tips of among the profitable Singapore property buyers. I believe many novice investors will profit quite a bit from studying and making use of some of the tips shared by the gurus." – Woo Chee Hoe Special bonus for consumers of Secrets of Singapore Property Gurus Actually, I can't consider one other resource on the market that teaches you all the points above about Singapore property at such a low value. Can you? Condominium For Sale (D09) – Yong An Park For Lease

In 12 months 2013, c ommercial retails, shoebox residences and mass market properties continued to be the celebrities of the property market. Models are snapped up in report time and at document breaking prices. Builders are having fun with overwhelming demand and patrons need more. We feel that these segments of the property market are booming is a repercussion of the property cooling measures no.6 and no. 7. With additional buyer's stamp responsibility imposed on residential properties, buyers change their focus to commercial and industrial properties. I imagine every property purchasers need their property funding to understand in value.

According to quantum mechanics (in the single-electron approximation), the electrons in any material have wavefunctions which can be described by the following Schrödinger equation:

(p22m+V)ψ=Eψ

where p is the quantum-mechanical momentum operator, V is the potential, and m is the mass of an electron. (This equation neglects the spin-orbit effect; see below.)

In a crystalline solid, V is a periodic function, with the same periodicity as the crystal lattice. Bloch's theorem proves that the solutions to this differential equation can be written as follows:

ψn,k(x)=eikxun,k(x)

where k is a vector (called the wavevector), n is a discrete index (called the band index), and un,k is a function with the same periodicity as the crystal lattice.

For any given n, the associated states are called a band. In each band, there will be a relation between the wavevector k and the energy of the state En,k, called the band dispersion. Calculating this dispersion is one of the primary applications of k·p perturbation theory.

Perturbation theory

DTZ's public sale group in Singapore auctions all forms of residential, workplace and retail properties, outlets, homes, lodges, boarding homes, industrial buildings and development websites. Auctions are at present held as soon as a month.

We will not only get you a property at a rock-backside price but also in an space that you've got longed for. You simply must chill out back after giving us the accountability. We will assure you 100% satisfaction. Since we now have been working in the Singapore actual property market for a very long time, we know the place you may get the best property at the right price. You will also be extremely benefited by choosing us, as we may even let you know about the precise time to invest in the Singapore actual property market.

The Hexacube is offering new ec launch singapore business property for sale Singapore investors want to contemplate. Residents of the realm will likely appreciate that they'll customize the business area that they wish to purchase as properly. This venture represents one of the crucial expansive buildings offered in Singapore up to now. Many investors will possible want to try how they will customise the property that they do determine to buy by means of here. This location has offered folks the prospect that they should understand extra about how this course of can work as well.

Singapore has been beckoning to traders ever since the value of properties in Singapore started sky rocketing just a few years again. Many businesses have their places of work in Singapore and prefer to own their own workplace area within the country once they decide to have a everlasting office. Rentals in Singapore in the corporate sector can make sense for some time until a business has discovered a agency footing. Finding Commercial Property Singapore takes a variety of time and effort but might be very rewarding in the long term.

is changing into a rising pattern among Singaporeans as the standard of living is increasing over time and more Singaporeans have abundance of capital to invest on properties. Investing in the personal properties in Singapore I would like to applaud you for arising with such a book which covers the secrets and techniques and tips of among the profitable Singapore property buyers. I believe many novice investors will profit quite a bit from studying and making use of some of the tips shared by the gurus." – Woo Chee Hoe Special bonus for consumers of Secrets of Singapore Property Gurus Actually, I can't consider one other resource on the market that teaches you all the points above about Singapore property at such a low value. Can you? Condominium For Sale (D09) – Yong An Park For Lease

In 12 months 2013, c ommercial retails, shoebox residences and mass market properties continued to be the celebrities of the property market. Models are snapped up in report time and at document breaking prices. Builders are having fun with overwhelming demand and patrons need more. We feel that these segments of the property market are booming is a repercussion of the property cooling measures no.6 and no. 7. With additional buyer's stamp responsibility imposed on residential properties, buyers change their focus to commercial and industrial properties. I imagine every property purchasers need their property funding to understand in value.

The periodic function un,k satisfies the following Schrödinger-type equation:[1]

Hkun,k=En,kun,k

where the Hamiltonian is

Hk=p22m+kpm+2k22m+V

Note that k is a vector consisting of three real numbers with units of inverse length, while p is a vector of operators; to be explicit,

kp=kx(ix)+ky(iy)+kz(iz)

In any case, we write this Hamiltonian as the sum of two terms:

H=H0+Hk,H0=p22m+V,Hk=2k22m+kpm

This expression is the basis for perturbation theory. The "unperturbed Hamiltonian" is H0, which in fact equals the exact Hamiltonian at k=0 (i.e., at the Gamma point). The "perturbation" is the term Hk. The analysis that results is called "k·p perturbation theory", due to the term proportional to k·p. The result of this analysis is an expression for En,k and un,k in terms of the energies and wavefunctions at k=0.

Note that the "perturbation" term Hk gets progressively smaller as k approaches zero. Therefore, k·p perturbation theory is most accurate for small values of k. However, if enough terms are included in the perturbative expansion, then the theory can in fact be reasonably accurate for any value of k in the entire Brillouin zone.

Expression for a nondegenerate band

For a nondegenerate band (i.e., a band which has a different energy at k=0 from any other band), with an extremum at k=0, and with no spin-orbit coupling, the result of k·p perturbation theory is (to lowest nontrivial order):[1]

un,k=un,0+mnnun,0|kp|un,0En,0En,0un,0
En,k=En,0+2k22m+2m2nn|un,0|kp|un,0|2En,0En,0

The parameters that are required to do these calculations, namely En,0 and un,0|p|un,0, are typically inferred from experimental data. (The latter are called "optical matrix elements".)

In practice, the sum over n' often includes only the nearest one or two bands, since these tend to be the most important (due to the denominator). However, for improved accuracy, especially at larger k, more bands must be included, as well as more terms in the perturbative expansion than the ones written above.

Effective mass

Mining Engineer (Excluding Oil ) Truman from Alma, loves to spend time knotting, largest property developers in singapore developers in singapore and stamp collecting. Recently had a family visit to Urnes Stave Church.

Using the expression above for the energy dispersion relation, a simplified expression for the effective mass in the conduction band of a semiconductor can be found.[3] To approximate the dispersion relation in the case of the conduction band, take the energy En0 as the minimum conduction band energy Ec0 and include in the summation only terms with energies near the valence band maximum, where the energy difference in the denominator is smallest. (These terms are the largest contributions to the summation.) This denominator is then approximated as the band gap Eg, leading to an energy expression:

Ec(k)Ec0+(k)22m+2Egm2n|uc,0|kp|un,0|2

The effective mass in direction ℓ is then:

1m=12m2Ec(k)kkm1m+2Egm2m,nuc,0|p|un,0un,0|pm|uc,0

Ignoring the details of the matrix elements, the key consequences are that the effective mass varies with the smallest bandgap and goes to zero as the gap goes to zero.[3] A useful approximation for the matrix elements in direct gap semiconductors is:[4]

2Egm2m,n|uc,0|p|un,0||uc,0|pm|un,0|20eV1mEg,

which applies within about 15% or better to most group-IV, III-V and II-VI semiconductors.[5]

In contrast to this simple approximation, in the case of valence band energy the spin-orbit interaction must be introduced (see below) and many more bands must be individually considered. The calculation is provided in Yu and Cardona.[6] In the valence band the mobile carriers are holes. One finds there are two types of hole, named heavy and light, with anisotropic masses.

k·p model with spin-orbit interaction

Including the spin-orbit interaction, the Schrödinger equation for u is:[2]

Hkun,k=En,kun,k

where

Hk=p22m+kpm+2k22m+V+14m2c2(σ×V)(k+p)

where σ=(σx,σy,σz) is a vector consisting of the three Pauli matrices. This Hamiltonian can be subjected to the same sort of perturbation-theory analysis as above.

Calculation in degenerate case

For degenerate or nearly degenerate bands, in particular the valence bands in certain materials such as gallium arsenide, the equations can be analyzed by the methods of degenerate perturbation theory.[1][2] Models of this type include the "Luttinger-Kohn model" (a.k.a. "Kohn-Luttinger model"),[7] and the "Kane model".[8]

Notes and references

43 year old Petroleum Engineer Harry from Deep River, usually spends time with hobbies and interests like renting movies, property developers in singapore new condominium and vehicle racing. Constantly enjoys going to destinations like Camino Real de Tierra Adentro.

See also

Template:Col-begin Template:Col-1-of-2 Electronic band structure

Band properties

Template:Col-2-of-2 Wavefunctions

Fundamental theory

Template:Col-end

  1. 1.0 1.1 1.2 1.3 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  2. 2.0 2.1 2.2 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  3. 3.0 3.1 3.2 20 year-old Real Estate Agent Rusty from Saint-Paul, has hobbies and interests which includes monopoly, property developers in singapore and poker. Will soon undertake a contiki trip that may include going to the Lower Valley of the Omo.

    My blog: http://www.primaboinca.com/view_profile.php?userid=5889534
  4. A direct gap semiconductor is one where the valence band maximum and conduction band minimum occur at the same position in k-space, usually the so-called Γ-point where k = 0.
  5. See Table 2.22 in Yu & Cardona, op. cit.
  6. See Yu & Cardona, op. cit. pp. 75-82
  7. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang
  8. One of the biggest reasons investing in a Singapore new launch is an effective things is as a result of it is doable to be lent massive quantities of money at very low interest rates that you should utilize to purchase it. Then, if property values continue to go up, then you'll get a really high return on funding (ROI). Simply make sure you purchase one of the higher properties, reminiscent of the ones at Fernvale the Riverbank or any Singapore landed property Get Earnings by means of Renting

    In its statement, the singapore property listing - website link, government claimed that the majority citizens buying their first residence won't be hurt by the new measures. Some concessions can even be prolonged to chose teams of consumers, similar to married couples with a minimum of one Singaporean partner who are purchasing their second property so long as they intend to promote their first residential property. Lower the LTV limit on housing loans granted by monetary establishments regulated by MAS from 70% to 60% for property purchasers who are individuals with a number of outstanding housing loans on the time of the brand new housing purchase. Singapore Property Measures - 30 August 2010 The most popular seek for the number of bedrooms in Singapore is 4, followed by 2 and three. Lush Acres EC @ Sengkang

    Discover out more about real estate funding in the area, together with info on international funding incentives and property possession. Many Singaporeans have been investing in property across the causeway in recent years, attracted by comparatively low prices. However, those who need to exit their investments quickly are likely to face significant challenges when trying to sell their property – and could finally be stuck with a property they can't sell. Career improvement programmes, in-house valuation, auctions and administrative help, venture advertising and marketing, skilled talks and traisning are continuously planned for the sales associates to help them obtain better outcomes for his or her shoppers while at Knight Frank Singapore. No change Present Rules

    Extending the tax exemption would help. The exemption, which may be as a lot as $2 million per family, covers individuals who negotiate a principal reduction on their existing mortgage, sell their house short (i.e., for lower than the excellent loans), or take part in a foreclosure course of. An extension of theexemption would seem like a common-sense means to assist stabilize the housing market, but the political turmoil around the fiscal-cliff negotiations means widespread sense could not win out. Home Minority Chief Nancy Pelosi (D-Calif.) believes that the mortgage relief provision will be on the table during the grand-cut price talks, in response to communications director Nadeam Elshami. Buying or promoting of blue mild bulbs is unlawful.

    A vendor's stamp duty has been launched on industrial property for the primary time, at rates ranging from 5 per cent to 15 per cent. The Authorities might be trying to reassure the market that they aren't in opposition to foreigners and PRs investing in Singapore's property market. They imposed these measures because of extenuating components available in the market." The sale of new dual-key EC models will even be restricted to multi-generational households only. The models have two separate entrances, permitting grandparents, for example, to dwell separately. The vendor's stamp obligation takes effect right this moment and applies to industrial property and plots which might be offered inside three years of the date of buy. JLL named Best Performing Property Brand for second year running

    The data offered is for normal info purposes only and isn't supposed to be personalised investment or monetary advice. Motley Fool Singapore contributor Stanley Lim would not personal shares in any corporations talked about. Singapore private home costs increased by 1.eight% within the fourth quarter of 2012, up from 0.6% within the earlier quarter. Resale prices of government-built HDB residences which are usually bought by Singaporeans, elevated by 2.5%, quarter on quarter, the quickest acquire in five quarters. And industrial property, prices are actually double the levels of three years ago. No withholding tax in the event you sell your property. All your local information regarding vital HDB policies, condominium launches, land growth, commercial property and more

    There are various methods to go about discovering the precise property. Some local newspapers (together with the Straits Instances ) have categorised property sections and many local property brokers have websites. Now there are some specifics to consider when buying a 'new launch' rental. Intended use of the unit Every sale begins with 10 p.c low cost for finish of season sale; changes to 20 % discount storewide; follows by additional reduction of fiftyand ends with last discount of 70 % or extra. Typically there is even a warehouse sale or transferring out sale with huge mark-down of costs for stock clearance. Deborah Regulation from Expat Realtor shares her property market update, plus prime rental residences and houses at the moment available to lease Esparina EC @ Sengkang