Exchange-based two-qubit gate for singlet-triplet qubits

被引：40

作者：

Wardrop, Matthew P. ^{[1
]}

Doherty, Andrew C. ^{[1
]}

机构：

[1] Univ Sydney, Sch Phys, Ctr Engn Quantum Syst, Sydney, NSW 2006, Australia

来源：

PHYSICAL REVIEW B | 2014年 / 90卷 / 04期

关键词：

QUANTUM COMPUTATION; ELECTRON SPIN; OSCILLATIONS;

D O I：

10.1103/PhysRevB.90.045418

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

We analyze a simple exchange-based two-qubit gate for singlet-triplet qubits in gate-defined semiconductor quantum dots that can be implemented in a single exchange pulse. Excitations from the logical subspace are suppressed by a magnetic field gradient that causes spin-flip transitions to be non-energy-conserving. We show that the use of adiabatic pulses greatly reduces leakage processes comapred to square pulses. We also characterize the effect of charge noise on the entanglement fidelity of the gate both analytically and in simulations; demonstrating high entanglement fidelities for physically realistic experimental parameters. Specifically we find that it is possible to achieve fidelities and gate times that are comparable to single-qubit states using realistic magnetic field gradients.

引用

页数：10

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