Suppressing gate errors in frequency-domain quantum computation through extra physical systems coupled to a cavity

We propose a scheme for frequency-domain quantum computation (FDQC) in which the errors due to crosstalk are suppressed using extra physical systems coupled to a cavity. FDQC is a promising method to realize large-scale quantum computation, but crosstalk is a major problem. When physical systems employed as qubits satisfy specific resonance conditions, gate errors due to crosstalk increase. In our scheme, the errors are suppressed by controlling the resonance conditions using extra physical systems.

Figure 1

A model of $N+N^{\prime }$ four-level systems including extra physical systems.

Figure 2

Contour diagram of gate errors in a three-qubit system [11].

Figure 3

Contour diagram of gate errors in a three-qubit system with three extra physical systems.

Figure 4

Implementation of proposed FDQC. (a) A device to implement our scheme. (b) State assignment. (c) Assignment of qubits and extra physical systems in the frequency domain.