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We elucidate the multi-particle transport of pair- and spin-tunnelings in strongly correlated interfaces. Not only usual single-particle tunneling but also interaction-induced multi-particle tunneling processes naturally arise from a…

Quantum Gases · Physics 2024-03-20 Hiroyuki Tajima , Daigo Oue , Mamoru Matsuo

We study the quantum charge noise and measurement properties of the double Cooper pair resonance point in a superconducting single-electron transistor (SSET) coupled to a Josephson charge qubit. Using a density matrix approach for the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 A. A. Clerk , S. M. Girvin , A. K. Nguyen , A. D. Stone

Tunable Josephson harmonics open new avenues for qubit design. We demonstrate a superconducting circuit element consisting of a tunnel junction in series with a SQUID loop, yielding a Josephson potential whose harmonic content is strongly…

A general method for directly measuring the low-frequency flux noise (below 10 Hz) in compound Josephson junction superconducting flux qubits has been used to study a series of 85 devices of varying design. The variation in flux noise…

We investigate the influence of nonstationary 1/f^mu noise, produced by interacting defects, on a quantum two-level system. Adopting a simple phenomenological model for this noise we describe exactly the corresponding dephasing in various…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Josef Schriefl , Maxime Clusel , David Carpentier , Pascal Degiovanni

The performance of various superconducting devices operating at ultra-low temperatures is impaired by the presence of non-equilibrium quasiparticles. Inelastic quasiparticle (QP) tunneling across Josephson junctions in superconducting…

Quantum Physics · Physics 2024-05-14 Plamen Kamenov , Thomas DiNapoli , Michael Gershenson , Srivatsan Chakram

Superconducting qubits are among the most promising candidates for building quantum computers. Despite significant improvements in qubit coherence, achieving a fault-tolerant quantum computer remains a major challenge, largely due to…

Quantum Physics · Physics 2024-07-12 Xuexin Xu

We predict a huge interference effect contributing to the conductance through large ultra-clean quantum dots of chaotic shape. When a double-dot structure is made such that the dots are the mirror-image of each other, constructive…

Mesoscale and Nanoscale Physics · Physics 2013-03-11 Robert S. Whitney , P. Marconcini , M. Macucci

The high-Q harmonic oscillator mode of a Josephson junction can be used as a novel probe of spurious two-level systems (TLSs) inside the amorphous oxide tunnel barriers of the junction. In particular, we show that spectroscopic transmission…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 L. Tian , R. W. Simmonds

The effects of Macroscopic Quantum Tunneling (MQT) and Coulomb Blockade (CB) in Josephson junctions are of considerable significance both for the manifestations of quantum mechanics on the macroscopic scale and potential technological…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hermann Grabert , Gert-Ludwig Ingold

The low-temperature quasi-universal behavior of amorphous solids has been attributed to the existence of spatially-localized tunneling defects found in the low-energy regions of the potential energy landscape. Computational models of…

Disordered Systems and Neural Networks · Physics 2023-01-05 Felix C. Mocanu , Ludovic Berthier , Simone Ciarella , Dmytro Khomenko , David R. Reichman , Camille Scalliet , Francesco Zamponi

Tunnelling between non-centrosymmetric superconductors with significant spin-orbit splitting is studied theoretically in a two-band treatment of the problem. We find that the critical Josephson current may be modulated by changing the…

Superconductivity · Physics 2007-05-23 K. Børkje , A. Sudbø

We develop a field theory formulation for the interaction of an ensemble of two-level tunneling systems (TLS) with the electronic states of a superconductor. Predictions for the impact of two-level tunneling systems on superconductivity are…

Superconductivity · Physics 2025-07-24 Junguang He , Wei-Ting Lin , J. A. Sauls

Spectral density of current fluctuations in a short ballistic superconducting quantum point contact is calculated for arbitrary bias voltages $V$. Contrary to a common opinion that the supercurrent flow in Josephson junctions is coherent…

Condensed Matter · Physics 2009-10-28 D. Averin , H. Imam

The edge channels of two-dimensional topological systems are protected from elastic reflection and are noiseless at low temperature. Yet, noise and cross-correlations can be induced when electron waves partly transmit to the opposite edge…

Mesoscale and Nanoscale Physics · Physics 2015-10-20 Fabrizio Dolcini

We study effects of infrared radiations on a two-dimensional BCS superconductor coupled with a normal metal substrate through a tunneling barrier. The phase transition conditions are analyzed by inspecting stability of the system against…

Superconductivity · Physics 2018-07-25 Huiying Liu , Junren Shi

We investigate quantum tunneling of two repulsive bosons in a triple-well potential subject to a high-frequency driving field. By means of the multiple-time-scale asymptotic analysis, we evidence a far-resonant strongly-interacting regime…

Quantum Physics · Physics 2015-06-15 Zheng Zhou , Wenhua Hai , Qiongtao Xie , Jintao Tan

New experiments that measure the low-frequency shot-noise spectrum at local tunneling contacts on mesoscopic structures are proposed. The current fluctuation spectrum at a single tunneling tip is determined by local partial densities of…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Thomas Gramespacher , Markus Buttiker

The exact microscopic structure of the environments that produces $1/f$ noise in superconducting qubits remains largely unknown, hindering our ability to have robust simulations and harness the noise. In this paper we show how it is…

Quantum Physics · Physics 2022-04-22 Miha Papič , Inés de Vega

Atomic-scale junctions are a powerful tool to study quantum transport, and are frequently examined through the mechanically controllable break junction technique (MCBJ). The junction-to-junction variation of atomic configurations often…

Mesoscale and Nanoscale Physics · Physics 2014-11-12 Ruoyu Chen , Manuel Matt , Fabian Pauly , Peter Nielaba , Juan Carlos Cuevas , Douglas Natelson