English
Related papers

Related papers: Few-mode to mesoscopic junctions in gatemon qubits

200 papers

We observe a series of discontinuities in the above gap current/voltage characteristics of highly transmissive Nb/Si superconductor/semiconductor interfaces. The bias at which each switch occurs decreases in quantized steps as a function of…

Superconductivity · Physics 2009-10-30 M. J. Black , B. W. Alphenaar , H. Ahmed

Coherence of superconducting qubits can be improved by implementing designs that protect the parity of Cooper pairs on superconducting islands. Here, we introduce a parity-protected qubit based on voltage-controlled semiconductor nanowire…

Quasiparticle tunneling across a Josephson junction sets a limit for the lifetime of a superconducting qubit state. We develop a general theory of the corresponding decay rate in a qubit controlled by a magnetic flux. The flux affects…

Mesoscale and Nanoscale Physics · Physics 2011-06-07 G. Catelani , Jens Koch , L. Frunzio , R. J. Schoelkopf , M. H. Devoret , L. I. Glazman

Junctionless Nanowire Field-Effect Transistors (JNFETs), where the channel region is uniformly doped without the need for source-channel and drain-channel junctions or lateral doping abruptness, are considered an attractive alternative to…

Emerging Technologies · Computer Science 2014-04-02 Mostafizur Rahman , Pritish Narayanan , Csaba Andras Moritz

Semiconductor-superconductor hybrid nanowires are a leading material platform for the realization of Majorana zero modes. The semiconductors in previous studies are dominantly InAs or InSb. In this work, we show the induced…

Quantum bits, or qubits, are an example of coherent circuits envisioned for next-generation computers and detectors. A robust superconducting qubit with a coherent lifetime of $O$(100 $\mu$s) is the transmon: a Josephson junction…

Quantum Physics · Physics 2020-05-11 J. M. Kreikebaum , K. P. O'Brien , A. Morvan , I. Siddiqi

We have constructed a new type of amplifier whose primary purpose is the readout of superconducting quantum bits. It is based on the transition of an RF-driven Josephson junction between two distinct oscillation states near a dynamical…

Superconductivity · Physics 2009-11-10 I. Siddiqi , R. Vijay , F. Pierre , C. M. Wilson , M. Metcalfe , C. Rigetti , L. Frunzio , M. H. Devoret

We theoretically study the macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap one such as ${MgB}_{2}$ and iron-based superconductors. In such a Josephson…

Quantum Physics · Physics 2011-02-11 Yukihiro Ota , Masahiko Machida , Tomio Koyama

We study fractional Josephson effect in a particle-number conserving system consisting of a quasi-one-dimensional superconductor coupled to a nanowire or an edge carrying $e/m$ fractional charge excitations with $m$ being an odd integer. We…

Mesoscale and Nanoscale Physics · Physics 2015-10-28 Meng Cheng , Roman M. Lutchyn

The observation of the gate-controlled supercurrent (GCS) effect in superconducting nanostructures increased the hopes for realizing a superconducting equivalent of semiconductor field-effect transistors. However, recent works attribute…

Two dimensional SrTiO3-based interfaces stand out among non-centrosymmetric superconductors due to their intricate interplay of gate tunable Rashba spin-orbit coupling and multi-orbital electronic occupations, whose combination…

We propose an active mechanism for coupling the quantized mode of a nanomechanical resonator to the persistent current in the loop of a superconducting Josephson junction (or phase slip) flux qubit. This coupling is independently controlled…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Fei Xue , Y. D Wang , C. P. Sun , H. Okamoto , H. Yamaguchi , K. Semba

As low-loss non-linear elements, Josephson junctions are the building blocks of superconducting qubits. The interaction of the qubit degree of freedom with the quasiparticles tunneling through the junction represent an intrinsic relaxation…

Mesoscale and Nanoscale Physics · Physics 2011-08-25 G. Catelani , R. J. Schoelkopf , M. H. Devoret , L. I. Glazman

We have carried out systematic Macroscopic Quantum Tunneling (MQT) experiments on Nb/Al-AlO_x/Nb Josephson junctions (JJs) of different areas. Employing on-chip lumped element inductors, we have decoupled the JJs from their environmental…

Superconductivity · Physics 2010-11-19 Christoph Kaiser , Roland Schäfer , Michael Siegel

The anharmonicity of a transmon qubit, defined as the difference in energy level spacing, is a key design parameter. In transmons built from hybrid superconductor-semiconductor Josephson elements, the anharmonicity is tunable with gate…

Epitaxial semiconductor-superconductor hybrid materials are an excellent basis for studying mesoscopic and topological superconductivity, as the semiconductor inherits a hard superconducting gap while retaining tunable carrier density.…

Mesoscale and Nanoscale Physics · Physics 2017-03-10 D. Sherman , J. S. Yodh , S. M. Albrecht , J. Nygård , P. Krogstrup , C. M. Marcus

Scaling superconducting quantum processors to large qubit counts faces challenges in control signal delivery, thermal management, and hardware complexity, particularly in achieving microwave signal multiplexing and long-distance quantum…

Quantum Physics · Physics 2025-09-30 Mustafa Bakr

We demonstrate rapid, first-order sideband transitions between a superconducting resonator and a frequency-modulated transmon qubit. The qubit contains a substantial asymmetry between its Josephson junctions leading to a linear portion of…

We theoretically study the DC Josephson effect of a semiconductor nanowire (NW) with strong spin-orbit interaction when a magnetic field is applied parallel to the NW. We adopt a model of single scatterer in a quasi-one-dimensional system…

Mesoscale and Nanoscale Physics · Physics 2013-04-15 Tomohiro Yokoyama , Mikio Eto , Yuli V. Nazarov

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