Related papers: Mode specific backscattering in a quantum point co…
Two-terminal conductance quantization in the context of quantum Hall (QH) physics is intimately related to the current carried by a discrete number of chiral edge modes. Upon pinching off a QH bar, one may engineer setups where some modes…
Graphene quantum point contacts (QPCs) in the quantum Hall regime host competing transport mechanisms including chiral edge propagation, valley degeneracy, and gate-induced mode mixing. Their interplay is not visible in conductance alone.…
Quantum computing can be realized with numerous different hardware platforms and computational protocols. A highly promising approach to foster scalability is to apply a photonic platform combined with a measurement-induced quantum…
Quantum interference can profoundly affect charge transport in single molecules, but experiments can usually measure only the conductance at the Fermi energy. Because in general the most pronounced features of the quantum interference are…
Quantum point contacts (QPC) are a key instrument in investigating the physics of edge excitations in the quantum Hall effect. However, at not-so-high bias voltage values, the predictions of the conventional point QPC model often deviate…
Charge carriers in the quantum Hall regime propagate via one-dimensional conducting channels that form along the edges of a two-dimensional electron gas. Controlling their transmission through a gate-tunable constriction, also called…
We experimentally study quantized conductance in an electrostatically defined constriction in a high-mobility InAs two-dimensional electron gas. A parallel magnetic field lifts the spin degeneracy and allows for the observation of plateaus…
The geometric measure of entanglement of variational quantum states is studied on the basis of its relation with the mean value of spin. We examine n-qubit quantum states prepared by a variational circuit with a layer formed by the…
The counterpropagating edge states of a two-dimensional topological insulator (TI) carry electrons of opposite spins. We investigate the transport properties of edge states in a two-dimensional TI which is contacted to ferromagnetic leads.…
We report the observation of an anomalous conductance plateau near G = 0.5 G0 (G0 = 2e2/h) in asymmetrically biased AlGaAs/GaAs quantum point contacts (QPCs), with in-plane side gates in the presence of lateral spin-orbit coupling. This is…
The metallic tip of a scanning force microscope operated at 300 mK is used to locally induce a potential in a fully controllable double quantum dot defined via local anodic oxidation in a GaAs/AlGaAs heterostructure. Using scanning gate…
Developing fast, accurate and scalable techniques for quantum state readout is an active area in semiconductor-based quantum computing. Here, we present results on dispersive sensing of silicon corner state quantum dots coupled to…
Quantum point contacts (QPC) are the building blocks of quantum dot qubits and semiconducting quantum electrical metrology circuits. QPCs also make highly sensitive electrical amplifiers with the potential to operate in the quantum-limited…
Apart from usual quantization steps on the ballistic conductance of a quasi-one-dimensional conductor, an additional plateau-like feature appears at a fraction of about 0.7 below the first conductance step in GaAs-based quantum point…
We have observed hysteresis between the forward and reverse sweeps of a common mode bias applied to the two in-plane side gates of an asymmetrically biased GaAs quantum point contact. The size of the hysteresis loop increases with the…
The semiconductor quantum point contact has long been a focal point for studies of one-dimensional electron transport. Their electrical properties are typically studied using ac conductance methods, but recent work has shown that the dc…
We calculate the non-linear conductance of a quantum point contact using the non-equilibrium Greens function technique within the Hartree approximation of spinless electrons. We quantitative reproduce the 0.25-anomaly in the differential…
Low temperature transport measurements on a p-GaAs quantum point contact are presented which reveal the presence of a conductance anomaly that is markedly different from the conventional `0.7 anomaly'. A lateral shift by asymmetric gating…
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…
Charge fluctuations of a large quantum dot coupled to a two-dimensional lead via a single-mode good Quantum Point Contact (QPC) and capacitively coupled to a back-gate, are investigated in the presence of a parallel magnetic field. The…