Related papers: Evaluating charge noise acting on semiconductor qu…
Dispersive charge sensing is realized in hybrid semiconductor-superconductor nanowires in gate-defined single- and double-island device geometries. Signal-to-noise ratios (SNRs) were measured both in the frequency and time domain.…
The entanglement dynamics of a pair of donor-based charge qubits is obtained in analytical form. The disentanglement is induced by off resonant scattering of acoustical phonons in the semiconductor host. According to our results a rather…
Characterizing noise in superconducting qubits is essential for improving coherence and gate performance. Conventional noise-sensing methods typically use the qubit itself as the sensor, which limits both accessible bandwidth and…
Semiconductor quantum dots driven by the broadband radiation fields of nearby quantum point contacts provide an exciting new setting for probing dynamics in driven quantum systems at the nanoscale. We report on real-time charge-sensing…
We demonstrate a 12 quantum dot device fabricated on an undoped Si/SiGe heterostructure as a proof-of-concept for a scalable, linear gate architecture for semiconductor quantum dots. The device consists of 9 quantum dots in a linear array…
In the presence of direct trajectories connecting source and drain contacts, the conductance of a quantum dot may exhibit resonances of the Fano type. Since Fano resonances result from the interference of two transmission pathways, their…
An ideal quantum dot spin qubit architecture requires a local magnetic field for one-qubit rotations. Such an inhomogeneous magnetic field, which could be implemented via a micromagnet, couples the qubit subspace with background charge…
We investigate the noise properties of a GaAs/AlGaAs resonant tunneling structure at bias voltages where the current characteristic is determined by single electron tunneling. We discuss the suppression of the shot noise in the framework of…
Motivated by activities of several experimental groups we investigate electron transport through two coherent, strongly coupled quantum dots ("double quantum dots"), taking into account both intra- and inter-dot Coulomb interactions. The…
Spin qubits in semiconductor quantum dots are one of the promizing devices to realize a quantum processor. A better knowledge of the noise sources affecting the coherence of such a qubit is therefore of prime importance. In this work, we…
Superconducting qubits with in-situ tunable properties are important for constructing a quantum computer. Qubit tunability, however, often comes at the expense of increased noise sensitivity. Here, we propose a flux-tunable superconducting…
Electron-phonon coupling is known to play an important role in the charge dynamics of semiconductor quantum dots. Here we explore its role in the combined charge-photon dynamics of cavity-coupled double quantum dots. Previous work on these…
Spins in semiconductor quantum dots are a candidate for cryogenic quantum processors due to their exceptionally long coherence times. One major challenge to scaling quantum dot spin qubits is the dense wiring requirements, making it…
Short dephasing times pose one of the main challenges in realizing a quantum computer. Different approaches have been devised to cure this problem for superconducting qubits, a prime example being the operation of such devices at optimal…
In quantum computation, quantum coherence must be maintained during gate operation. However, in physical implementations, various couplings with the environment are unavoidable and can lead to a dephasing of a quantum bit(qubit). The…
We study the charge noise $S_Q$ in Josephson qubits produced by fluctuating two level systems (TLS) with electric dipole moments in the substrate. The TLS are driven by an alternating electric field of angular frequency $\Omega$ and…
A better understanding of the noise causing qubit decoherence is crucial for improving qubit performance. The noise spectrum affecting the qubit may be extracted by measuring dephasing under the application of pulse sequences but requires…
Semiconductor quantum dots host a rich manifold of excitonic complexes, including neutral excitons that emit anti-bunched single photons and charged exciton complexes capable of producing super-bunched photons via cascade emission.…
A quantum kinetic theory is used to compute excitation induced dephasing in semiconductor quantum dots due to the Coulomb interaction with a continuum of states, such as a quantum well or a wetting layer. It is shown that a frequency…
In this paper, we carry out a theoretical analysis of the zero-frequency and finite-frequency shot noise in electron tunneling through a two-level interacting system connected to two leads, when a coherent coupling between the two levels is…