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Related papers: Coupling spin qubits via superconductors

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The interplay between various many body effects in a quantum dot attached to two normal and one superconducting lead is considered in the limit of large superconducting gap. By the proximity effect the superconducting lead induces pairing…

Mesoscale and Nanoscale Physics · Physics 2015-06-17 Grzegorz Michalek , Bogdan R. Bulka , Tadeusz Domanski , Karol I. Wysokinski

Conducting altermagnets have recently emerged as intriguing materials supporting strongly spin-polarized currents without magnetic stray fields. We demonstrate that altermagnets enable three key functionalities, merging superconductivity…

Superconductivity · Physics 2024-10-23 Hans Gløckner Giil , Bjørnulf Brekke , Jacob Linder , Arne Brataas

We propose an efficient mechanism for the operation of writing spin in a quantum dot, which is an ideal candidate for qubit. The idea is based on the Andreev reflection induced spin polarization (ARISP) in a ferromagnetic / quantum-dot /…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Yu Zhu , Qing-feng Sun , Tsung-han Lin

We simulate the control of the spin states in a two-electron double quantum dot when an external detuning potential is used for passing the system through an anticrossing. The hyperfine coupling of the electron spins with the surrounding…

Mesoscale and Nanoscale Physics · Physics 2011-04-12 Jani Särkkä , Ari Harju

Novel effects emerge from an interplay between multiple Andreev reflections and Coulomb interaction in quantum dot coupled to superconducting leads and subject to a finite potential bias $V$. Combining an intuitive physical picture with…

Strongly Correlated Electrons · Physics 2009-10-31 Yshai Avishai , Anatoly Golub , Andrei D. Zaikin

We report on conductance measurements in carbon nanotube based double quantum dots connected to two normal electrodes and a central superconducting finger. By operating our devices as beam splitters, we provide evidence for Crossed Andreev…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 L. G. Herrmann , F. Portier , P. Roche , A. Levy Yeyati , T. Kontos , C. Strunk

We use a hybrid superconductor-semiconductor transmon device to perform spectroscopy of a quantum dot Josephson junction tuned to be in a spin-1/2 ground state with an unpaired quasiparticle. Due to spin-orbit coupling, we resolve two…

The interaction of qubits via microwave frequency photons enables long-distance qubit-qubit coupling and facilitates the realization of a large-scale quantum processor. However, qubits based on electron spins in semiconductor quantum dots…

Mesoscale and Nanoscale Physics · Physics 2017-12-27 Mónica Benito , X. Mi , J. M. Taylor , J. R. Petta , Guido Burkard

We construct a theory of coherent transport through a ballistic quantum dot coupled to a superconductor. We show that the leading-order quantum correction to the two-terminal conductance of these Andreev quantum dots may change sign…

Mesoscale and Nanoscale Physics · Physics 2009-12-16 Robert S. Whitney , Ph. Jacquod

Electron transport properties in a parallel double-quantum-dot structure with three-terminals are theoretically studied. By introducing a local Rashba spin-orbit coupling, we find that an incident electron from one terminal can select a…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Weijiang Gong , Yisong Zheng

We study resonant tunneling through a superconducting double barrier structure in graphene as a function of the system parameters. At each barrier, due to the proximity effect, an incident electron can either reflect as an electron or a…

Mesoscale and Nanoscale Physics · Physics 2015-05-19 Arijit Kundu , Sumathi Rao , Arijit Saha

We propose a new method to measure the coherence time of superconducting phase qubits based on the analysis of the magnetic-field dependent dc nonlinear Andreev current across a high-resistance tunnel contact between the qubit and a dirty…

Condensed Matter · Physics 2007-05-23 Mikhail V. Feigel'man , Lev B. Ioffe , Vadim B. Geshkenbein , Gianni Blatter

We study superconducting quantum interference in InSb flake Josephson junctions. An even-odd effect in the amplitude and periodicity of the superconducting quantum interference pattern is found. Interestingly, the occurrence of this pattern…

Quantum gates between spin qubits can be implemented leveraging the natural Heisenberg exchange interaction between two electrons in contact with each other. This interaction is controllable by electrically tailoring the overlap between…

We study a double quantum dot each dot of which is tunnel-coupled to superconducting leads. In the Coulomb blockade regime, a spin-dependent Josephson coupling between two superconductors is induced, as well as an antiferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Mahn-Soo Choi , C. Bruder , Daniel Loss

Coherent interactions at a distance provide a powerful tool for quantum simulation and computation. The most common approach to realize an effective long-distance coupling 'on-chip' is to use a quantum mediator, as has been demonstrated for…

Mesoscale and Nanoscale Physics · Physics 2016-10-11 T. A. Baart , T. Fujita , C. Reichl , W. Wegscheider , L. M. K. Vandersypen

We study theoretically the differential conductance at a junction between a time reversal symmetry broken spin orbit coupled system with a tunable band gap and a superconductor. We look for spin-dependent Andreev reflection (i.e, sub-gap…

Mesoscale and Nanoscale Physics · Physics 2018-12-14 Dibya Kanti Mukherjee , Joanna Hutchinson , Arijit Kundu

Quantum computers have the potential to solve certain interesting problems significantly faster than classical computers. To exploit the power of a quantum computation it is necessary to perform inter-qubit operations and generate entangled…

Mesoscale and Nanoscale Physics · Physics 2013-04-09 Michael D. Shulman , Oliver E. Dial , Shannon P. Harvey , Hendrik Bluhm , Vladimir Umansky , Amir Yacoby

We present a real-time diagrammatic theory for transport through interacting quantum dots tunnel coupled to normal and superconducting leads. Our formulation describes both the equilibrium and non-equilibrium superconducting proximity…

Superconductivity · Physics 2008-09-05 Michele Governale , Marco G. Pala , Jürgen König

We present a proof-of-principle of how electronic transport measurements permits the observation of the Autler-Townes doublet, an optical property of nanodevices. The quantum physical system consists of one optically pumped quantum dot, a…

Mesoscale and Nanoscale Physics · Physics 2018-08-24 M. O. Assunção , G. S. Diniz , L. Sanz , F. M. Souza