Phase gate of one superconducting qubit simultaneously controlling n qubits in a cavity

TL;DR

This paper proposes a method to implement a multi-qubit controlled-phase gate in superconducting qubits within a cavity, with operation time independent of the number of qubits, enhancing quantum gate efficiency.

Contribution

It introduces a three-step controlled-phase gate for superconducting qubits that operates simultaneously on multiple qubits with fixed operation time, regardless of qubit number.

Findings

Operation time is independent of the number of qubits involved.

The gate is insensitive to the initial cavity state.

It enables simultaneous multi-qubit CNOT gate implementation.

Abstract

We propose how to realize a three-step controlled-phase gate of one superconducting qubit simultaneously controlling n qubits selected from N qubits in a cavity (1<n<N). The operation time of this gate is independent of the number n of qubits involved in the gate operation. This phase gate controlling at once n qubits is insensitive to the initial state of the cavity mode and can be used to produce an analogous CNOT gate simultaneously acting on n qubits.