相关论文: Anamolous conductance plateau in an asymmetrically…
The integer quantized conductance of one-dimensional electron systems is a well understood effect of quantum confinement. A number of fractionally quantized plateaus are also commonly observed. They are attributed to many-body effects, but…
Features below the first conductance plateau in ballistic quantum point contacts (QPCs) are often ascribed to electron interaction and spin effects within the single mode limit. In QPCs with a highly asymmetric geometry, we observe sharp…
Strong spin-orbit coupling, the resulting large $g$ factor, and small effective mass make InAs an attractive material platform for inducing topological superconductivity. The surface Fermi level pinning in the conduction band enables highly…
We describe the transport properties of a 5 $\mu$m long one-dimensional (1D) quantum wire. Reduction of conductance plateaux due to the introduction of weakly disorder scattering are observed. In an in-plane magnetic field, we observe…
Small differential conductance oscillations as a function of source-drain bias were observed and systematically studied in an asymmetric quantum point contact (QPC). These oscillations become significantly suppressed in a small in-plane…
We theoretically investigate the dynamical nuclear spin polarization in a quantum point contact (QPC) at finite magnetic field. We find that when the QPC is tuned to be spin selective, at the conductance of e^2/h, a finite bias induces a…
We have recently shown that asymmetric lateral spin orbit coupling (LSOC) resulting from the lateral in-plane electric field of the confining potential of a side-gated quantum point contact (QPC) can be used to create a strongly spin-…
In this letter, we report the magneto-electronic properties of high mobility InAs quantum point contacts grown on InP substrates. The 1D conductance reaches a maximum value of 17 plateaus, quantized in units of 2e^2/h, where e is the…
Linear conductance below $2e^2/h$ shows resonance peaks in highly asymmetric quantum point contacts (QPCs). As the channel length increases, the number of peaks also increases. At the same time, differential conductance exhibits zero bias…
We study the onset of intrinsic bistability and accompanying hysteresis in a single quantum point contact (QPC) with in-plane side gates in the presence of lateral spin-orbit coupling. The hysteresis in the conductance versus common gate…
We have studied ballistic transport in a 1D channel formed using surface gate techniques on a back-gated, high-mobility, bilayer 2D hole system. At millikelvin temperatures, robust conductance quantization is observed in the quantum wire…
Quantum spin transport is studied in an interacting quantum dot. It is found that a conductance "plateau" emerges in the non-linear charge conductance by a spin bias in the Kondo regime. The conductance plateau, as a complementary to the…
We demonstrate that conductance anomalies can arise in a clean, adiabatic quantum point contact when a channel is partially transmitting. Even for a smooth barrier potential, backscattering induces Friedel oscillations that, via electron…
We propose a new device to create a tunable all-electric spin polarizer: a quantum point contact (QPC) with four gates -- two in-plane side gates in series. The first pair of gates, near the source, is asymmetrically biased to create spin…
Conductance measurements of carbon nanotubes containing gated local depletion regions exhibit plateaus as a function of gate voltage, spaced by approximately e2/h, the quantum of conductance for a single (non-degenerate) mode. Plateau…
Experiments on quantum point contacts have highlighted an anomalous conductance plateau at $0.7 (2e^2/h)$, with features suggestive of the Kondo effect. Here we present an Anderson model for transport through a point contact which we…
We measure the transmission phase of a quantum point contact (QPC) at a low carrier density in which electron interaction is expected to play an important role and anomalous behaviors are observed. In the first conductance plateau, the…
We study ballistic transport through semiconductor quantum point contact systems under different confinement geometries and applied fields. In particular, we investigate how the {\em lateral} spin-orbit coupling, introduced by asymmetric…
Self-consistent modelling based on local spin-density formalism is employed to calculate conductance of quantum point contacts at finite temperatures. The total electrostatic potential exhibits spin-dependent splitting, which persists at…
The $\nu = 2/3$ fractional quantum Hall state is the hole-conjugate state to the primary Laughlin $\nu = 1/3$ state. We investigate transmission of edge states through quantum point contacts fabricated on a GaAs/AlGaAs heterostructure…