Title




Electrical and thermalproperties of a 2dimensional electrongas in a onedimensional periodic potential
 
Author




 
Abstract




We investigate the influence of a periodic weak modulation along the x direction on the electrical and thermal properties of a twodimensional electron gas in the presence of a perpendicular magnetic field. The modulation lifts the degeneracy of the Landau levels and leads to onedimensional magnetic bands whose bandwidth oscillates as a function of the magnetic field. At weak magnetic fields this gives rise to the Weiss oscillations in the magnetoresistance, discovered recently, which have a very weakly temperaturedependent amplitude and a period proportional to squareroot n(e), when n(e) is the electron density. Diffusioncurrent contributions, proportional to the square of the bandwidth, dominate rho(xx), and collisional contributions, varying approximately as the square of the density of states, dominate rho(yy). The result is that rho(xx) and rho(yy) oscillate out of phase as observed. Asymptotic analytical expressions are presented for the conductivity tensor. Similar oscillations, of much smaller amplitude, occur in the thermodynamic quantities, such as the magnetization, the susceptibility, and the specific heat. We also predict oscillations in the Hall resistance, the cyclotron resonance position, the linewidth, as well as in the thermal conductivity and thermopower. The components of the thermalresistance tensor have a magneticfield dependence similar to that of the electricalresistivity tensor. 
 
Language




English
 
Source (journal)




Physical review : B : condensed matter and materials physics.  Lancaster, Pa, 1998  2015
 
Publication




Lancaster, Pa
:
1992
 
ISSN




10980121
[print]
1550235X
[online]
 
Volume/pages




46
:8
(1992)
, p. 46674680
 
ISI




A1992JK72500032
 
Full text (Publisher's DOI)




 
Full text (open access)




 
