Charge noise suppression in capacitively coupled singlet-triplet spin qubits under magnetic field

Abstract

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 demonstrated in several types of spin qubits, the existence of one for coupled singlet-triplet qubits is unclear. We theoretically demonstrate, using full configuration-interaction calculations, that a range of nearly sweet spots appear in the coupled singlet-triplet qubit system when a strong enough magnetic field is applied externally. We further demonstrate that ramping to and from the judiciously chosen nearly sweet spot using sequences based on the shortcut to adiabaticity offers maximal gate fidelities under charge noise and phonon-induced decoherence. These results should facilitate realization of high-fidelity two-qubit gates in singlet-triplet qubit systems.

5+28 pages, 4+19 figures

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Cited by in corpus (4)

• Limits to Quantum Gate Fidelity from Near-Field Thermal and Vacuum Fluctuations
• Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
• Theory on electron-phonon spin dehphasing in GaAs multi-electron double quantum dots
• Limitations on the maximal level of entanglement of two singlet-triplet qubits in GaAs quantum dots