Role of wide contacts in the ac response of a double-barrier structure

被引:6
作者
Quan, Jun
Yu, Yabin [1 ]
Tang, Y. H.
机构
[1] Hunan Univ, Dept Appl Phys, Changsha 410082, Peoples R China
[2] Hunan Univ, Coll Mat Sci & Engn, Changsha 410082, Peoples R China
关键词
D O I
10.1103/PhysRevB.73.195314
中图分类号
T [工业技术];
学科分类号
08 ;
摘要
The role of wide contacts is investigated in the ac response of a double-barrier structure. Several physical quantities, such as the distributions of internal potential and charge density, capacitance, and low-frequency ac conductance, are calculated. The results show that when the system is far away from resonance, the charge distribution exists only around the barrier regions as a response to the applied voltage, and hence the contacts have almost no effect on the results. In the resonant case or near resonance, the charge distribution displays large peaks in the contact regions, but almost no charge distribution within the conductor. In the case of small transmission probability, we find a considerable amount of charge distribution both in the contact regions and surrounding the double-barrier conductor. Moreover, we find that qualitatively the presence of contacts does not change the main features of the emittance obtained from a calculation that neglects the widening of contacts. But the contact effect on the capacitance is significant when the chemical potential is very close to the resonant energy: There is a sharp capacitance peak at the resonance, which corresponds to the charge peaks in the contact regions.
引用
收藏
页数:7
相关论文
共 28 条
[1]   Nonuniversal conductance quantization in high-quality quantum wires [J].
Alekseev, AY ;
Cheianov, VV .
PHYSICAL REVIEW B, 1998, 57 (12) :R6834-R6837
[2]   Interaction constants and dynamic conductance of a gated wire [J].
Blanter, YM ;
Hekking, FWJ ;
Buttiker, M .
PHYSICAL REVIEW LETTERS, 1998, 81 (09) :1925-1928
[3]   CAPACITANCE, ADMITTANCE, AND RECTIFICATION PROPERTIES OF SMALL CONDUCTORS [J].
BUTTIKER, M .
JOURNAL OF PHYSICS-CONDENSED MATTER, 1993, 5 (50) :9361-9378
[4]  
BUTTIKER M, 1993, PHYS REV LETT, V70, P4114, DOI 10.1103/PhysRevLett.70.4114
[5]   CURRENT PARTITION IN MULTIPROBE CONDUCTORS IN THE PRESENCE OF SLOWLY OSCILLATING EXTERNAL POTENTIALS [J].
BUTTIKER, M ;
THOMAS, H ;
PRETRE, A .
ZEITSCHRIFT FUR PHYSIK B-CONDENSED MATTER, 1994, 94 (1-2) :133-137
[6]   LUTTINGER LIQUID THEORY OF ONE-DIMENSIONAL QUANTUM FLUIDS .1. PROPERTIES OF THE LUTTINGER MODEL AND THEIR EXTENSION TO THE GENERAL 1D INTERACTING SPINLESS FERMI GAS [J].
HALDANE, FDM .
JOURNAL OF PHYSICS C-SOLID STATE PHYSICS, 1981, 14 (19) :2585-2609
[7]   TRANSMISSION THROUGH BARRIERS AND RESONANT TUNNELING IN AN INTERACTING ONE-DIMENSIONAL ELECTRON-GAS [J].
KANE, CL ;
FISHER, MPA .
PHYSICAL REVIEW B, 1992, 46 (23) :15233-15262
[8]   RESONANT CONDUCTION IN BALLISTIC QUANTUM CHANNELS [J].
KIRCZENOW, G .
PHYSICAL REVIEW B, 1989, 39 (14) :10452-10455
[9]   Transport through quasiballistic quantum wires: The role of contacts [J].
Lal, S ;
Rao, S ;
Sen, D .
PHYSICAL REVIEW LETTERS, 2001, 87 (02) :1-026801
[10]  
Landau L. D., 1958, QUANTUM MECH NONRELA