Related papers: Spin Bias Measurement Based on a Quantum Point Con…
We present studies of the Coulomb blockade and Kondo regimes of transport through a quantum dot connected to current leads through spin-polarizing quantum point contacts (QPCs). This structure, arising from the effect of lateral spin-orbit…
We present measurements of current noise in quantum point contacts as a function of source-drain bias, gate voltage, and in-plane magnetic field. At zero bias, Johnson noise provides a measure of the electron temperature. At finite bias,…
We compute the spin current rectification coefficient of a non-equilibrium quantum dot subject to a spin bias and an {\it ac} charge bias with small amplitude. As a function of the position of the resonant level the spin current…
A quantum point contact (QPC) patterned on a two-dimensional electron gas is investigated with a scanning gate setup operated at a temperature of 300 mK. The conductance of the point contact is recorded while the local potential is modified…
Electron transport properties in a triple-quantum-dot ring with three terminals are theoretically studied. By introducing local Rashba spin-orbit interaction on an individual quantum dot, we calculate the charge and spin currents in one…
We review progress on the spintronics proposal for quantum computing where the quantum bits (qubits) are implemented with electron spins. We calculate the exchange interaction of coupled quantum dots and present experiments, where the…
We report high-bandwidth charge sensing measurements using a GaAs quantum point contact embedded in a radio frequency impedance matching circuit (rf-QPC). With the rf-QPC biased near pinch-off where it is most sensitive to charge, we…
We demonstrate a mesoscopic spin polarizer/analyzer system that allows the spin polarization of current from a quantum point contact in an in-plane magnetic field to be measured. A transverse focusing geometry is used to couple current from…
We propose realistic methods to detect local spin polarization, which utilize a quantum dot side coupled to the target system. By choosing appropriate states in the dot, we can put spin selectivity to the dot and detect spins in the target…
Single spin measurement represents a major challenge for spin-based quantum computation. In this article we propose a new method for measuring the spin of a single electron confined in a quantum dot (QD). Our strategy is based on entangling…
Spin effects in the transport properties of a quantum dot with spin-charge separation are investigated. It is found that the non-linear transport spectra are dominated by spin dynamics. Strong spin polarization effects are observed in a…
The applications of spin-based quantum sensors to measurements probing fundamental physics are surveyed. Experimental methods and technologies developed for quantum information science have rapidly advanced in recent years, and these tools…
We study the interplay of control and parameter estimation on a quantum spin chain. A single qubit probe is attached to one end of the chain, while we wish to estimate a parameter on the other end. We find that control on the probe qubit…
Transmission through a quantum point contact (QPC) in the quantum Hall regime usually exhibits multiple resonances as a function of gate voltage and high nonlinearity in bias. Such behavior is unpredictable and changes sample by sample.…
Spin-dependent transport measurements through a double quantum dot are a valuable tool for detecting both the coherent evolution of the spin state of a single electron as well as the hybridization of two-electron spin states. In this paper,…
Coulomb drag between two quantum wires is exponentially sensitive to the mismatch of their electronic densities. The application of a magnetic field can compensate this mismatch for electrons of opposite spin directions in different wires.…
Scanning gate microscopy is used to locally investigate electron transport in a high-mobility two-dimensional electron gas formed in a GaAs/AlGaAs heterostructure. Using quantum point contacts (QPC) we observe branches caused by electron…
Correlation is a fundamental statistical measure of order in interacting quantum systems. In solids, electron correlations govern a diverse array of material classes and phenomena such as heavy fermion compounds, Hunds metals, high-Tc…
Quantum point contacts (QPCs) are commonly employed to capacitively detect the charge state of coupled quantum dots (QD). An indirect back-action of a biased QPC onto a double QD laterally defined in a GaAs/AlGaAs heterostructure is…
We uncover a fundamental effect of the QED vacuum in an external electromagnetic (EM) field. We show that the quantized vacuum of electrons is spin polarized by the EM field and manifests as a vacuum spin current. An experiment is proposed…