Controlled-NOT logic with nonresonant Josephson phase qubits

TL;DR

This paper derives theoretical bounds on qubit detuning necessary for high-fidelity CNOT gate implementation using Josephson phase qubits, providing guidelines for optimal control sequences.

Contribution

It introduces specific bounds on qubit detuning for effective CNOT gates with Josephson phase qubits, advancing quantum gate fidelity control.

Findings

Qubit detuning must not exceed 2g for two-step sequences.

Qubit detuning must not exceed g for single-step sequences.

Provides theoretical limits for high-fidelity quantum gate operations.

Abstract

We establish theoretical bounds on qubit detuning for high fidelity controlled-NOT logic gate implementations with weakly coupled Josephson phase qubits. It is found that the value of qubit detuning during the entangling pulses must not exceed 2g for two-step, and g for single-step control sequences, where g is the relevant coupling constant.