Related papers: Gate-defined quantum point contacts in a germanium…
We study non-equilibrium differential conductance and current fluctuations in a single quantum point contact. The two-terminal electrical transport properties -- differential conductance and shot noise -- are measured at 1.5 K as a function…
The quiet quantum environment of holes in solid-state devices has been at the core of increasingly reliable architectures for quantum processors and memories.1-6 However, due to the lack of scalable materials to properly tailor the valence…
We report on transport experiments through high-mobility gate-tunable undoped InSb QWs. Due to the elimination of any Si modulation doping, the gate-defined two-dimensional electron gases in the quantum wells display a significantly…
We report magneto-transport measurements in wide GaAs quantum wells with tunable density to probe the stability of the fractional quantum Hall effect at filling factor $\nu = $ 5/2 in the vicinity of the crossing between Landau levels (LLs)…
We have developed a theory of the longitudinal $g$ factor of light holes in semiconductor quantum wells. It is shown that the absolute value of the light-hole $g$-factor can strongly exceed its value in the bulk and, moreover, the…
Hole-based spin qubits in strained planar germanium quantum wells have received considerable attention due to their favourable properties and remarkable experimental progress. The sizeable spin-orbit interaction in this structure allows for…
We investigate theoretically the fractional quantum Hall effect at half-filling in the lowest Landau level observed in asymmetric wide quantum wells. The asymmetry can be achieved by a potential bias applied between the two sides of the…
Quantum dots can confine single electrons or holes to define spin qubits that can be operated with high fidelity. Experimental work has progressed from linear to two-dimensional arrays of quantum dots, enabling qubit interactions that are…
The conductance for tunneling through a point contact between two $\nu =1/3$ quantum Hall edges is described by a universal scaling function, which has recently been measured experimentally. We compute this universal function exactly, by…
Quantum Hall edge channels can be combined with metallic regions to fractionalize electrons and form correlated impurity models. We study a minimal device, that has been experimentally achieved quite recently, with two floating islands…
We have realized encapsulated trilayer MoS$_2$ devices with gated graphene contacts. In the bulk, we observe an electron mobility as high as 7000~cm$^{2}$/(V s) at a density of 3 $\times$ 10$^{12}$~cm$^{-2}$ at a temperature of 1.9~K.…
We demonstrated that a triple-gated GaAs quantum point contact, which has an additional surface gate between a pair of split gates to strengthen the lateral confinement, produces the well-defined quantized conductance and Fabry-P\'erot-type…
Strongly correlated electron liquids which occur in quantizing magnetic fields reveal a cornucopia of fascinating quantum phenomena such as fractionally charged quasiparticles, anyonic statistics, topological order, and many others. Probing…
We have studied a near-surface two-dimensional electron gas based on an InAs quantum well on a GaAs substrate. In devices without a dielectric layer we estimated large electron mobilities on the order of $10^5$ cm$^2$/Vs. We have observed…
On the basis of the Chalker-Coddington network model, a numerical and analytical study is made of the statistics of point-contact conductances for systems in the integer quantum Hall regime. In the Hall plateau region the point-contact…
We consider two-dimensional Fermi systems with quadratic band touching and $C_3$ symmetry, as realizable in Bernal-stacked honeycomb bilayers. Within a renormalization-group analysis, we demonstrate the existence of a quantum critical point…
We report on the fabrication and electronic transport characterisation of Schottky-gated strongly confined Si/SiGe quantum point contacts (QPC). At zero magnetic field and T=450mK the QPC conductance as a function of gate voltage shows a…
Coulomb effects on the edge states of a two dimensional electron gas in the presence of a high magnetic field are studied for different widths of the boundaries. Schr\"odinger and Poisson equations are selfconsistently solved in the integer…
We theoretically investigate the optical functionality of a semiconducting quantum ring manipulated by two electrostatic lateral gates used to induce a double quantum well along the ring. The well parameters and corresponding inter-level…
We study numerically conductance fluctuations near the integer quantum Hall effect plateau transition. The system is presumed to be in a mesoscopic regime, with phase coherence length comparable to the system size. We focus on a…