Proposal for realizing a multiqubit tunable phase gate of one qubit simultaneously controlling n target qubits using cavity QED

TL;DR

This paper proposes a fast, scalable multiqubit tunable phase gate in cavity QED systems, controlling multiple target qubits simultaneously with minimal intra-cavity pulse interference, applicable to various quantum platforms.

Contribution

It introduces a method for implementing a multiqubit phase gate using first-order large detuning, independent of qubit number, avoiding intra-cavity pulse application challenges.

Findings

Gate operation time is independent of the number of qubits.

The method is applicable to superconducting qubits, NV centers, and quantum dots.

Fast gate operation due to first-order large detuning.

Abstract

We propose a way to realize a multiqubit tunable phase gate of one qubit simultaneously controlling n target qubits with atoms in cavity QED. In this proposal, classical pulses interact with atoms outside a cavity only, thus the experimental challenge of applying a pulse to an intra-cavity single atom without affecting other atoms in the same cavity is avoided. Because of employing a first-order large detuning, the gate can be performed fast when compared with the use of a second-order large detuning. Furthermore, the gate operation time is independent of the number of qubits. This proposal is quite general, which can be applied to various superconducting qubits coupled to a resonator, NV centers coupled to a microsphere cavity or quantum dots in cavity QED.