English
Related papers

Related papers: Dephasing of Majorana-based qubits

200 papers

We study numerically the influence of momentum-conserving dephasing on the transport in a disordered chain of scatterers. Loss of phase memory is caused by coupling the transport channels to dephasing reservoirs. In contrast to previously…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 I. Knittel , F. Gagel , M. Schreiber

We investigate the dynamics of a charge qubit consisting of two Coulomb-blockaded islands hosting Majorana zero modes. The frequency of the qubit is determined by coherent single-electron tunneling between two islands originating from the…

Mesoscale and Nanoscale Physics · Physics 2021-06-02 Jukka I. Väyrynen , Dmitry I. Pikulin , Roman M. Lutchyn

We relate disentanglement and decoherence rates in a pair of three-level atoms subjected to multi-local and collective pure dephasing noise acting in a preferred basis. The bipartite entanglement decay rate, as bounded from above by the…

Quantum Physics · Physics 2017-08-23 Gregg Jaeger , Kevin Ann

The characterization and mitigation of decoherence in natural and artificial two-level systems (qubits) is fundamental to quantum information science and its applications. Decoherence of a quantum superposition state arises from the…

A quantum computer that can be constructed based on a superconducting nanocircuits has previously been proposed. We examine the effect of background charge fluctuations on a coupled Josephson charge qubit system used in such a computer. In…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Toshifumi Itakura , Yasuhiro Tokura

We analyze the charge-noise induced coherence time $T_2$ of the fluxonium qubit as a function of the number of array junctions in the device, $N$. The pure dephasing rate decreases with $N$, but we find that the relaxation rate increases,…

Quantum Physics · Physics 2020-08-05 Ari Mizel , Yariv Yanay

The braiding of two non-Abelian Majorana modes is important for realizing topological quantum computation. It can be achieved through tuning the coupling between the two Majorana modes to be exchanged and two ancillary Majorana modes.…

Quantum Physics · Physics 2019-07-24 Zhen-Tao Zhang , Feng Mei , Xiang-Guo Meng , Bao-Long Liang , Zhen-Shan Yang

We demonstrate the suppression of photon shot noise dephasing in a superconducting qubit by eliminating its dispersive coupling to the readout cavity. This is achieved in a tunable coupling qubit, where the qubit frequency and coupling rate…

Quantum Physics · Physics 2017-01-23 Gengyan Zhang , Yanbing Liu , James J. Raftery , Andrew A. Houck

We propose an Aharonov-Bohm interferometer consisted of two topological superconducting chains (TSCs) to generate coherence of Majorana qubits, each qubit is made of two Majorana zero modes (MZMs) with the definite fermion parity. We obtain…

Mesoscale and Nanoscale Physics · Physics 2021-02-23 Fei-Lei Xiong , Hon-Lam Lai , Wei-Min Zhang

The observation of coherent quantum transport phenomena in metals and semiconductors is limited by the eventual loss of phase coherence of the conducting electrons. We use the weak localization effect to measure the low-temperature…

Mesoscale and Nanoscale Physics · Physics 2010-08-27 M. Eshkol , E. Eisenberg , M. Karpovski , A. Palevski

We show that the zero-point fluctuations of the intrinsic electromagnetic environment limit the phase coherence time in all mesoscopic systems at low temperatures. We derive this quantum noise limited dephasing time and its temperature…

Mesoscale and Nanoscale Physics · Physics 2009-10-30 P. Mohanty , R. A. Webb

We calculate the cumulants of the charge transmitted through a chaotic cavity in the limit that the two openings have a large number of scattering channels. The shot noise, which is the second cumulant, is known to be insensitive to…

Condensed Matter · Physics 2007-05-23 Ya. M. Blanter , H. Schomerus , C. W. J. Beenakker

We present measurements of 1/f frequency noise in both linear and Josephson-junction-embedded superconducting aluminum resonators in the low power, low temperature regime - typical operating conditions for superconducting qubits. The…

Superconductivity · Physics 2015-06-03 K. W. Murch , S. J. Weber , E. M. Levenson-Falk , R. Vijay , I. Siddiqi

A flux qubit can have a relatively long decoherence time at the degeneracy point, but away from this point the decoherence time is greatly reduced by dephasing. This limits the practical applications of flux qubits. Here we propose a new…

Superconductivity · Physics 2009-11-11 J. Q. You , Xuedong Hu , S. Ashhab , Franco Nori

We suggest and demonstrate a protocol which suppresses dephasing due to the low-frequency noise by qubit motion, i.e., transfer of the logical qubit of information in a system of $n \geq 2$ physical qubits. The protocol requires only the…

Mesoscale and Nanoscale Physics · Physics 2016-01-13 D. V. Averin , K. Xu , Y. P. Zhong , C. Song , H. Wang , Siyuan Han

Majorana zero modes (MZMs) are bound midgap topological excitations at the ends of a 1D topological superconductor, which must come in pairs. If the two MZMs in the pair are sufficiently well-separated by a distance much larger than their…

Mesoscale and Nanoscale Physics · Physics 2026-04-22 Haining Pan , Sankar Das Sarma

The interaction between solid-state qubits and their environmental degrees of freedom produces non-unitary effects like decoherence and dissipation. Uncontrolled decoherence is one of the main obstacles that must be overcome in quantum…

Quantum Physics · Physics 2014-11-24 Paula I. Villar , Fernando C. Lombardo

We have used Ramsey tomography to characterize charge noise in a weakly charge-sensitive superconducting qubit. We find a charge noise that scales with frequency as $1/f^\alpha$ over 5 decades with $\alpha = 1.93$ and a magnitude…

We investigate the pure dephasing of a Josephson qubit due to the spectral diffusion of two-level systems that are close to resonance with the qubit. We identify the parameter regime in which this pure dephasing rate can be of the order of…

Quantum Physics · Physics 2024-05-02 Shlomi Matityahu , Alexander Shnirman , Moshe Schechter

We propose a quadrupolar exchange-only spin (QUEX) qubit that is highly robust against charge noise and nuclear spin dephasing, the dominant decoherence mechanisms in quantum dots. The qubit consists of four electrons trapped in three…

Mesoscale and Nanoscale Physics · Physics 2018-10-31 Maximilian Russ , J. R. Petta , Guido Burkard