One-dimensional electron gas in GaAs: Periodic conductance oscillations as a function of density

Abstract

A narrow channel patterned in a novel GaAs heterostructure with tunable electron density is used to study the conductance of the electron gas in the very low-density regime where only a single one-dimensional subband is occupied. Periodic oscillations of the conductance versus density and nonlinearities in the conductance suggest the formation of a one-dimensional charge-density wave or Wigner crystal.A one-dimensional electronic system (1DES) is expected to have exotic quantum states, ' and has been the focus

Competition of disorder and interchain hopping in a two-chain Hubbard model

“…Besides its relevance to ladder compounds, the study of two-chain systems is also important for the study of transport in systems such as metallic carbon nanotubes [33,34] and quantum wires [35,36,37,38]. It has also a theoretical interest in itself since the interplay of localization and interaction in dimension higher than one remains poorly understood [39] and coupled quasi-one dimensional system may allow for a controlled study of the effect of increasing space dimensionality on disorder and interaction.…”

Coulomb-Regulated Conductance Oscillations in a Disordered Quantum Wire

“…The effcct was tentatively attributed to the formation of a charge density wave. A similar effect was secii subsequently in narrow channels in inverted GaAs-AlGaAs heterostructures [5], and was given the same Interpretation. As an alternative explanation, it was proposed by two of us [6] that the characteristic features of the experiment might be due to the Coulomb blockade of tunneling [7] -a single electron effect studied extensively in metals where quantum interference effects are negligible.…”

“…The charge density wave phenomenon [4,5,12] may play a role in such a theory, which however does not yet exist. Our present goal, in the spirit of Ref.…”

“…This is relevant to our experiments (and to related experiments [4,5,12,13]) to the extent that one channel segment, delimited by two strong scattering centers, effectively limits the channel conductance. In addition, it is a model for experiments on the Aharonov-Bohm effect in individual quantum dots [14,15,16].…”

“…[4] and in the channels defined by lateral p-n junctions of Ref. [5]. In our system a narrow channel is defined electrostatically in the two-dimensional electron gas by means of a split gate on top of the heterostructure.…”