Crosstalk analysis for simultaneously driven two-qubit gates in spin qubit arrays

Abstract

One of the challenges when scaling up semiconductor-based quantum processors consists in the presence of crosstalk errors caused by control operations on neighboring qubits. In previous work, crosstalk in spin qubit arrays has been investigated for non-driven single qubits near individually driven quantum gates and for two simultaneously driven single-qubit gates. Nevertheless, simultaneous gates are not restricted to single-qubit operations but also include frequently used two-qubit gates such as the CNOT gate. We analyse the impact of crosstalk drives on qubit operations, such as the CNOT and CPHASE gates. We investigate the case of parallel Y and CNOT gates, and we also consider a two-dimensional arrangement of two parallel CNOT gates and find unavoidable crosstalk. To minimize crosstalk errors, we develop appropriate control protocols.

Phase flip code with semiconductor spin qubits

“…errors occurring in the encoding, decoding and correction steps of the algorithm. These errors are caused by decoherence of the qubits, residual exchange between the qubits (see Supplementary Information section VI), cross talk [27,59] and imperfect two-qubit gates. When com-paring the results for the different input states of the data qubit, it becomes clear that for an input state |↓ of the data qubit the visibility is higher and the correction of the single-qubit errors is more successful.…”