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Related papers: Charge echo in a Cooper-pair box

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We study electron spin decoherence in a two-electron double quantum dot due to the hyperfine interaction, under spin-echo conditions as studied in recent experiments. We develop a semi-classical model for the interaction between the…

Mesoscale and Nanoscale Physics · Physics 2011-09-07 Izhar Neder , Mark S. Rudner , Hendrik Bluhm , Sandra Foletti , Bertrand I. Halperin , Amir Yacoby

We demonstrate a substantial improvement in the spin-exchange gate using symmetric control instead of conventional detuning in GaAs spin qubits, up to a factor-of-six increase in the quality factor of the gate. For symmetric operation,…

In this report, we examine the decoherence of a spin qubits system coupled to counted spin chain with a $1/r^2$ interaction by using influence functional. We also examine the time evolution of density matrix numerically when environment is…

Mesoscale and Nanoscale Physics · Physics 2008-12-20 Toshifumi Itakura

Silicon quantum devices are maturing from academic single- and two-qubit devices to industrially-fabricated dense quantum-dot (QD) arrays, increasing operational complexity and the need for better pulsed-gate and readout techniques. We…

In this study, we examine decoherence of qubits system coupled independently by using influence functional. We especially concentrated on the effect of qubit flip process. We examine the zero-dimensional qubit and one-dimensional qubits…

Quantum Physics · Physics 2008-09-30 Toshifumi Itakura

Many solid-state qubit systems are afflicted by low frequency noise mechanisms that operate along two perpendicular axes of the Bloch sphere. Depending on the qubit's control fields, either noise can be longitudinal or transverse to the…

Quantum Physics · Physics 2022-02-02 Guy Ramon , Łukasz Cywiński

The charge-phase Josephson qubit based on a superconducting single charge transistor inserted in a low-inductance superconducting loop is considered. The loop is inductively coupled to a radio-frequency driven tank circuit enabling the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 A. B. Zorin

Photon-echo based quantum memories use inhomogeneously broadened, optically thick ensembles of absorbers to store a weak optical signal and employ various protocols to rephase the atomic coherences for information retrieval. We study the…

Quantum Physics · Physics 2013-11-19 Gabor Demeter

The stimulated photon echo formed by the sequence of three laser excitation pulses in gaseous medium on the transition with the angular momentum change 0-1 is considered with an account of elastic depolarizing collisions. The polarization…

Atomic Physics · Physics 2012-11-02 V. A. Reshetov , E. N. Popov

We investigate the performance of dynamical decoupling methods at suppressing electron spin decoherence from a low-temperature nuclear spin reservoir in a quantum dot. The controlled dynamics is studied through exact numerical simulation,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon

We investigate the rephasing efficiency of sequences of phased pulses for spin echoes and light storage by electromagnetically induced transparency (EIT). We derive a simple theoretical model and show that the rephasing efficiency is very…

Quantum Physics · Physics 2018-12-31 Genko T. Genov , Daniel Schraft , Thomas Halfmann

We study theoretically the possibilities of coupling the quantum mechanical motion of a trapped charged particle (e.g. ion or electron) to quantum degrees of freedom of superconducting devices, nano-mechanical resonators and quartz bulk…

Quantum Physics · Physics 2017-03-01 Shlomi Kotler , Raymond W. Simmonds , Dietrich Leibfried , David J. Wineland

Spin-dependent photon echoes in combination with pump-probe Kerr rotation are used to study the microscopic electron spin transport in a CdTe/(Cd,Mg)Te quantum well in the hopping regime. We demonstrate that independent of the particular…

Recent experiments have demonstrated quantum manipulation of two-electron spin states in double quantum dots using electrically controlled exchange interactions. Here, we present a detailed theory for electron spin dynamics in two-electron…

Mesoscale and Nanoscale Physics · Physics 2012-10-19 J. M. Taylor , J. R. Petta , A. C. Johnson , A. Yacoby , C. M. Marcus , M. D. Lukin

Exchange-only (EO) spin qubits in silicon realise all-electrical qubit control through pairwise Heisenberg exchange interactions, making them attractive for scalable quantum computation. Their principal vulnerability is charge noise, which…

In this paper we study the low temperature kinetics of the electrons in the system composed of a quantum dot connected to two leads by solving the equation of motion. The decoherence and the relaxation of the system caused by the gate…

Strongly Correlated Electrons · Physics 2009-11-13 M. Q. Weng

Dielectric constant and absorption measurements on boron doped silicon samples show that transitions between the acceptor energy levels can be induced by an applied resonant ac electric field and the Stark tuning of level spacing with an…

Quantum Physics · Physics 2015-05-20 Y. P. Song , B. Golding

We describe how the spin coherence time of a localized electron spin in solids, i.e. a solid state spin qubit, can be prolonged by applying designed electron spin resonance pulse sequences. In particular, the spin echo decay due to the…

Mesoscale and Nanoscale Physics · Physics 2011-03-14 W. M. Witzel , S. Das Sarma

Full electric-field control of spin orientations is one of the key tasks in semiconductor spintronics. We demonstrate that electric field pulses can be utilized for phase-coherent +/- pi spin rotation of optically generated electron spin…

Materials Science · Physics 2012-10-05 S. Kuhlen , K. Schmalbuch , M. Hagedorn , P. Schlammes , M. Patt , M. Lepsa , G. Güntherodt , B. Beschoten

We consider a double quantum dot system with two embedded and non-aligned spin impurities to manipulate the magnitude and polarization of the electron spin density. The device is attached to semi-infinite one-dimensional leads which are…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Gianluca Stefanucci , Enrico Perfetto , Michele Cini