Charge-noise tolerant exchange gates of singlet-triplet qubits in asymmetric double quantum dots

Abstract

In the semi-conductor double quantum dot singlet-triplet qubit architecture, the decoherence caused by the qubit's charge environment poses a serious obstacle in the way towards large scale quantum computing. The effects of the charge decoherence can be mitigated by operating the qubit in the so called sweet spot regions where it is insensitive to electrical noise. In this paper, we propose singlet-triplet qubits based on two quantum dots of different sizes. Such asymmetric double dot systems allow the implementation of exchange gates with controllable exchange splitting $J$ operated in the doubly occupied charge region of the larger dot, where the qubit has high resilience to charge noise. In the larger dot, $J$ can be quenched to a value smaller than the intra-dot tunneling using magnetic fields, while the smaller dot and its larger splitting can be used in the projective readout of the qubit.

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Cited by in corpus (10)

• Reduced sensitivity to charge noise in semiconductor spin qubits via symmetric operation
• Noise suppression using symmetric exchange gates in spin qubits
• Three-electron spin qubits
• Non-Gaussian signatures and collective effects in charge noise affecting a dynamically-decoupled qubit
• Long-Range Interaction between Charge and Spin Qubits in Quantum Dots
• Validity of the single-particle description and charge noise resilience for multielectron quantum dots
• Quantum dot molecule devices with optical control of charge status and electronic control of coupling
• Nonmonotonic buildup of spin-singlet correlations in a double quantum dot
• A robust operating point for capacitively coupled singlet-triplet qubits
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