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Related papers: Decoherence of two coupled singlet-triplet spin qu…

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Engineered spin-electric coupling enables spin qubits in semiconductor nanostructures to be manipulated efficiently and addressed individually. While synthetic spin-orbit coupling using a micromagnet is widely used for driving qubits based…

We study the decay of entanglement of quantum dot electron-spin qubits under hyperfine interaction mediated decoherence. We show that two qubit entanglement of a single entangled initial state may exhibit decay characteristic of the two…

Quantum Physics · Physics 2014-06-25 Paweł Mazurek , Katarzyna Roszak , Ravindra W. Chhajlany , Paweł Horodecki

We study theoretically the phonon-induced relaxation and decoherence of spin states of two electrons in a lateral double quantum dot in a SiGe/Si/SiGe heterostructure. We consider two types of singlet-triplet spin qubits and calculate their…

Mesoscale and Nanoscale Physics · Physics 2018-05-29 Viktoriia Kornich , Christoph Kloeffel , Daniel Loss

Charge noise is the main hurdle preventing high-fidelity operation, in particular that of two-qubit gates, of semiconductor-quantum-dot-based spin qubits. While certain sweet spots where charge noise is substantially suppressed have been…

Mesoscale and Nanoscale Physics · Physics 2021-05-05 Guo Xuan Chan , Jason P. Kestner , Xin Wang

The effects of a nearby two-level charge fluctuator on a double-dot two-spin qubit are studied theoretically. Assuming no direct tunneling between the charge fluctuator and the qubit quantum dots, the Coulomb couplings between the qubit…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 Guy Ramon , Xuedong Hu

The qubit is the fundamental building block of a quantum computer. We fabricate a qubit in a silicon double quantum dot with an integrated micromagnet in which the qubit basis states are the singlet state and the spin-zero triplet state of…

Spin-orbit coupling is ubiquitous in quantum dot quantum computing architectures, and makes spin qubits susceptible to charge noise. We derive a Hamiltonian describing the effect of spin-orbit and noise on a single-spin qubit in a quantum…

Mesoscale and Nanoscale Physics · Physics 2014-11-14 Adam Bermeister , Daniel Keith , Dimitrie Culcer

We study the decoherence effect of charge noise on a single flip-flop qubit and two dipole-coupled qubits. We find that a single flip-flop qubit is highly resistant to charge noise at its sweet spots. However, due to the proximity of the…

Quantum Physics · Physics 2021-04-16 John Truong , Xuedong Hu

We have developed quantitative description of quantum coherent oscillations in the system of two coupled qubits in the presence of weak decoherence that in general can be correlated between the two qubits. It is shown that in the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Kristian Rabenstein , Dmitri V. Averin

Recent advances towards spin-based quantum computation have been primarily fuelled by elaborate isolation from noise sources, such as surrounding nuclear spins and spin-electric susceptibility, to extend spin coherence. In the meanwhile,…

Mesoscale and Nanoscale Physics · Physics 2018-03-21 J. Yoneda , K. Takeda , T. Otsuka , T. Nakajima , M. R. Delbecq , G. Allison , T. Honda , T. Kodera , S. Oda , Y. Hoshi , N. Usami , K. M. Itoh , S. Tarucha

Spin-orbit effects, inherent to electrons confined in quantum dots at a silicon heterointerface, provide a means to control electron spin qubits without the added complexity of on-chip, nanofabricated micromagnets or nearby coplanar…

Mesoscale and Nanoscale Physics · Physics 2022-02-04 Ryan M. Jock , N. Tobias Jacobson , Martin Rudolph , Daniel R. Ward , Malcolm S. Carroll , Dwight R. Luhman

We demonstrate by an explicit model calculation that the decay of entanglement of two two-state systems (two qubits) is governed by the product of the factors that measure the degree of decoherence of each of the qubits, subject to…

Quantum Physics · Physics 2010-10-12 D. Tolkunov , V. Privman , P. K. Aravind

Quantum dot-based spin qubits are resilient towards charge noise and are affected by magnetic noise only. However, environmental interaction leads to decoherence in these qubit systems. The external control parameters are directly related…

Mesoscale and Nanoscale Physics · Physics 2022-01-19 Tanmay Sarkar , Yash Tiwari , Vishvendra Singh Poonia

We present a study of the prospects for coherence preservation in solid-state spin qubits using dynamical decoupling protocols. Recent experiments have provided the first demonstrations of multipulse dynamical decoupling sequences in this…

Mesoscale and Nanoscale Physics · Physics 2013-05-29 M. J. Biercuk , H. Bluhm

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

We investigate coherent time-evolution of charge states (pseudo-spin qubit) in a semiconductor double quantum dot. This fully-tunable qubit is manipulated with a high-speed voltage pulse that controls the energy and decoherence of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Toshiaki Hayashi , Toshimasa Fujisawa , Hai-Du Cheong , Yoon-Ha Jeong , Yoshiro Hirayama

Spin qubits in Silicon quantum dots can have long coherence times, yet their manipulation relies on the exchange interaction, through which charge noise can induce decoherence. Charge traps near the interface of a Si heterostructure lead to…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Dimitrie Culcer , Xuedong Hu , S. Das Sarma

We study the dynamics of a pulse-gated semiconductor double quantum dot qubit. In our experiments, the qubit coherence times are relatively long, but the visibility of the quantum oscillations is low. We show that these observations are…

Singlet fission is commonly defined to involve a process by which an overall singlet state with local triplet structure spin-decoheres into two triplet states, thereby completing the fission process. This process, often defined in loose…

Chemical Physics · Physics 2020-07-29 Max Marcus , William Barford

We consider whether quantum coherence in the form of mutual entanglement between a pair of qubits is susceptible to decay that may be more rapid than the decay of the coherence of either qubit individually. An instance of potential…

Quantum Physics · Physics 2009-11-10 Ting Yu , J. H. Eberly
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