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

Abstract

We analyse 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 compared to square pulses. We also characterise 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.

12 pages + 7 pages supplementary info, 5 figures. Comments welcome. This version incorporates the changes made during the review process for PRB

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Cited by in corpus (5)

• Adiabatic many-body state preparation and information transfer in quantum dot arrays
• Long-range entanglement for spin qubits via quantum Hall edge modes
• Fault-Tolerant Quantum Computation for Singlet-Triplet Qubits with Leakage Errors
• Magic angle for barrier-controlled double quantum dots
• A robust operating point for capacitively coupled singlet-triplet qubits