Exchange - correlation effects in semiconductor double-quantum-wire systems

Abstract

We study the short-range correlations in a double-quantum-wire structure within the self-consistent scheme of Singwi, Tosi, Land, and Sjölander. The local-field factors and static correlation functions are calculated for electron and electron-hole double-wire systems. The ground-state energy and collective excitations are discussed. It is found that the interwire correlations become quite important for electron-hole systems. Comparisons with the randomphase approximation and Hubbard approximation are made for various calculated quantities.

Wigner crystallization in semiconductor quantum wires

“…Furthermore, the full correlation energy of the double-wire structure is not incorporated. Since the interwire correlation effects are much weaker than the intrawire correlations, 25 we believe that this approximation is also justified. In Fig.…”

Exchange-correlation effects in coupled quantum wire systems at finite temperature

“…Over past few decades, the coupled quantum wire systems have been intensively investigated experimentally [1][2][3][4][5][6][7][8][9] and theoretically [10][11][12][13][14][15][16][17][18][19][20] to uncover the new and incredibly rich physics emanating as a result of the intraand inter-wire many-particle interactions. Experimentally fabricated coupled quantum wire systems are composed of two parallely placed quantum wires having wire widths and inter-wire separation ∼of few nanometers.…”

“…In literature [10][11][12][13][14][15][16][17][18][19][20], a number of attempts have been made to investigate the ground-state properties of coupled quantum wire systems. Some of the prominent efforts made in this direction are related to the exploration of the possibility of CDW instability [10-12, 14, 17-19], calculation of plasmon energy [10,[14][15][16][17], ground-state energy [15,16,18], and the correlation energy [19]. Historically, Das Sarma and Hwang [13] have applied the random-phase approximation (RPA) to calculate the ground-state properties of a coupled electron quantum wire system.…”

“…Indisputably, the RPA completely ignores the short-range particle's correlations and is valid only in the high particle number density regime. However in the limit of low particle number density, it becomes crucial to include the exchange-correlations among the particles as it has been found [14][15][16][17][18][19] that the better estimation of the ground-state properties of these systems depends upon the accurate elucidation of the exchange-correlations.…”

“…As an improvement over the RPA, exchange-correlation effects among particles are taken into account through the self-consistent mean-field approximation of Singwi, Tosi, Land and Sjölander [21], the so called STLS theory. In the STLS theory, the bare Coulomb interaction potential among particles is modified through the time independent (static) local-field correction (LFC) factor and has already been proved to be very fruitful in studying the ground-state properties of coupled quantum wire [15][16][17] and quantum layer [22][23][24][25][26] systems. Gold [10] and Wang and Ruden [11] have applied the STLS theory to study the ground-state properties of an electron-electron quantum wire system and predicted the CDW instability by completely ignoring the interwire correlations.…”