Realization of efficient quantum gates with a superconducting qubit-qutrit circuit

TL;DR

This paper proposes a superconducting circuit with a qutrit and two qubits that efficiently performs various quantum gates, including entanglement, Toffoli, Fredkin, and geometric gates, advancing scalable quantum computing.

Contribution

It introduces a novel superconducting circuit design that enables efficient, robust, and universal quantum gates for complex quantum information processing.

Findings

Enables generation of entanglement between two qubits

Realizes conditional three-qubit gates like Toffoli and Fredkin

Implements a conditional geometric gate for holonomic quantum computing

Abstract

Building a quantum computer is a daunting challenge since it requires good control but also good isolation from the environment to minimize decoherence. It is therefore important to realize quantum gates efficiently, using as few operations as possible, to reduce the amount of required control and operation time and thus improve the quantum state coherence. Here we propose a superconducting circuit for implementing a tunable system consisting of a qutrit coupled to two qubits. This system can efficiently accomplish various quantum information tasks, including generation of entanglement of the two qubits and conditional three-qubit quantum gates, such as the Toffoli and Fredkin gates. Furthermore, the system realizes a conditional geometric gate which may be used for holonomic (non-adiabatic) quantum computing. The efficiency, robustness and universality of the presented circuit makes it a promising candidate to serve as a building block for larger networks capable of performing involved quantum computational tasks.