Related papers: Nonequilibrium interactions between two quantum ci…

We use the non-equilibrium bosonization technique to investigate effects of the Coulomb interaction on quantum Hall edge states at filing factor nu=2, partitioned by a quantum point contact (QPC). We find, that due to the integrability of…

The electron and current density distributions in the close proximity of quantum point contacts (QPCs) are investigated. A three dimensional Poisson equation is solved self-consistently to obtain the electron density and potential profile…

We theoretically study the non-equilibrium correlations and entanglement between distant semiconductor qubits in a one-dimensional coupled-mechanical-resonator chain. Each qubit is defined by a double quantum dot (DQD) and embedded in a…

We study a single-mode cavity weakly coupled to a voltage-biased quantum point contact. In a perturbative analysis, the lowest order predicts a thermal state for the cavity photons, driven by the emission noise of the conductor. The cavity…

Since the realization of high-quality microwave cavities coupled to quantum dots, one can envisage the possibility to investigate the coherent interaction of light and matter in semiconductor quantum devices. Here we study a parallel double…

We study the two-qubit controlled-not gate operating on qubits encoded in the spin state of a pair of electrons in a double quantum dot. We assume that the electrons can tunnel between the two quantum dots encoding a single qubit, while…

We calculate the noise spectrum of the output signal of a quantum detector during continuous measurement of a two-level system (qubit). We generalize the previous results obtained for the regime of high voltages (when $eV$ is much larger…

Nonreciprocal devices, such as isolator or circulator, are crucial for information routing and processing in quantum networks. Traditional nonreciprocal devices, which rely on the application of bias magnetic fields to break time-reversal…

We demonstrate that the presence of charge around a semiconductor quantum dot (QD) strongly affects its optical properties and produces non-resonant coupling to the modes of a microcavity. We first show that, besides (multi)exciton lines, a…

We study the time evolution of two electron spin states in a double quantum-dot system, which includes a nearby quantum point contact (QPC) as a measurement device. We obtain that the QPC measurement induced decoherence is in time scales of…

With the rapid scaling of superconducting quantum processors, electronic control systems relying on commercial off-the-shelf instruments face critical bottlenecks in signal density, power consumption, and crosstalk mitigation. Here we…

We explore the low-frequency noise of interacting electrons in a one-dimensional structure (quantum wire or interaction-coupled edge states) with counterpropagating modes, assuming a single channel in each direction. The system is driven…

Superconducting qubits hold promise for quantum computing, but their operation is challenged by various sources of noise, including excitations known as quasiparticles. Qubits with gap asymmetry larger than their transition energy are less…

Qubits are physical, a quantum gate thus not only acts on the information carried by the qubit but also on its energy. What is then the corresponding flow of energy between the qubit and the controller that implements the gate? Here we…

Coupled quantum dots are potential candidates for qubit systems in quantum computing. We use a non-invasive voltage probe to study the evolution of a coupled dot system from a situation where the dots are coupled to the leads to a situation…

The combined action of a DC bias and a microwave drive on the transport characteristic of a superconductor-quantum dot-superconductor junction is investigated. To cope with time dependent non-equilibrium effects and interactions in the…

We study an interferometric method for the measurement of the statistics of work performed on a driven quantum system, which has been put forward recently [Dorner et al., Phys. Rev. Lett. 110 230601 (2013), Mazzola et al., Phys. Rev. Lett.…

We study transport through a double quantum dot system in which each quantum dot is coupled to a phonon mode. Such a system can be realized, e.g., using a suspended carbon nanotube. We find that the interplay between strong electron-phonon…

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…

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…