Related papers: Quasiparticle cooling of a single-Cooper-pair-tran…
The electrons forming a Cooper pair in a superconductor can be spatially separated preserving their spin entanglement by means of quantum dots coupled to both the superconductor and independent normal leads. We investigate the…
We investigate quasiparticle tunneling in a Cooper-pair box which is embedded in a superconducting ring to allow control of the total phase difference across the island. The phase affects the transition rate between different electron…
We study dephasing of a superconducting qubit due to quasiparticle tunneling through a Josephson junction. While qubit decay due to tunneling processes is well understood within a golden rule approximation, pure dephasing due to BCS…
We present here our recent results on qubit reset scheme based on a quantum-circuit refrigerator (QCR). In particular, we use the photon-assisted quasiparticle tunneling through a…
The main purpose of this brief review is to present a sketch of the mechanism of high-Tc superconductivity based mainly on tunneling measurements in cuprates. In the review, we shall mostly discuss tunneling spectroscopy in Bi2212. Analysis…
The presence of quasiparticles in superconducting qubits emerges as an intrinsic constraint on their coherence. While it is difficult to prevent the generation of quasiparticles, keeping them away from active elements of the qubit provides…
We calculate the subgap current in planar superconducting tunnel junctions with thin-film diffusive leads. It is found that the subharmonic gap structure of the tunnel current scales with an effective tunneling transparency which may exceed…
A single static magnetic impurity in a fully-gapped superconductor leads to formation of an intragap quasiparticle bound state. At temperatures much below the superconducting transition, the energy relaxation and spin dephasing of the state…
Many superconducting devices rely on the finite gap in the excitation spectrum of a superconductor: thanks to this gap, at temperatures much smaller than the critical one the number of excitations (quasiparticles) that can impact the…
The Josephson quasiparticle (JQP) cycle in a voltage-biased superconducting single-electron transistor (SSET) combines coherent Cooper pair tunneling with incoherent quasiparticle decay. We have measured the influence of current flow…
We make a semiclassical analysis of thermal pair creations of quasiparticles at various filling factors in quantum Hall systems. It is argued that the gap energy is reduced considerably by the Coulomb potential made by impurities. It is…
A Cooper pair splitter consists of a central superconducting contact, S, from which electrons are injected into two parallel, spatially separated quantum dots (QDs). This geometry and electron interactions can lead to correlated electrical…
At low temperature, the concentration of quasiparticles observed in superconducting circuits far exceeds the predictions of microscopic BCS theory at equilibrium. As a source of dissipation, these excess quasiparticles degrade the…
We present experiments on single Cooper-pair transistors made of two different superconducting materials. We chose Ti and Al to create an energy gap profile such that the island has a higher gap than the leads, thereby acting as a barrier…
We study the thermopower of a quantum dot weakly coupled to two reservoirs by tunnel junctions. At low temperatures the transport through the dot is suppressed by charging effects (Coulomb blockade). As a result the thermopower shows an…
Quantum technology promises revolutionizing applications in information processing, communications, sensing, and modelling. However, efficient on-demand cooling of the functional quantum degrees of freedom remains a major challenge in many…
The exact expression for the phase-dependent linear conductance of a weakly damped superconducting quantum point contact is obtained. The calculation is performed by summing up the complete perturbative series in the coupling between the…
Evidence of a non-thermal magnetic relaxation in the intermediate state of a type-I superconducor is presented. It is attributed to quantum tunneling of interfaces separating normal and superconducting regions. Tunneling barriers are…
The ideal superconductor provides a pristine environment for the delicate states of a quantum computer: because there is an energy gap to excitations, there are no spurious modes with which the qubits can interact, causing irreversible…
We propose a model of quasiparticle tunneling across the high-$T_c$ superconductor-insulator-normal metal junction based on the different mechanisms for tunneling of electrons at positive bias and dissociating polaronic Cooper pairs and…