Realization of Universal Quantum Gates with Spin-Qudits in Colloidal Quantum Dots

TL;DR

This paper demonstrates how hyperfine interactions in a single Mn-ion within a quantum dot can be used to create a multi-level qudit system, enabling universal quantum gates with robustness against decoherence, advancing scalable quantum computing.

Contribution

It introduces a method to realize universal quantum gates using spin-qudits in colloidal quantum dots through hyperfine interactions and electron double resonance techniques.

Findings

Successful generation of superpositions between hyperfine states.

Experimental realization of NOT and SWAP gates.

Demonstrated robustness of gates against decoherence.

Abstract

We exploit hyperfine interactions in a single Mn-ion confined in a quantum dot (QD) to create a qudit, i.e. a multi-level quantum-bit system, with well defined, addressable and robust set of spin states for the realization of universal quantum gates. We generate and probe an arbitrary superposition of states between selected hyperfine energy level pairs by using electron double resonance detected nuclear magnetic resonance (EDNMR). This enables the observation of Rabi oscillations and the experimental realization of NOT and SWAP universal quantum gates that are robust against decoherence. Our protocol for cyclical preparation, manipulation and read-out of logic gates offers opportunities for integration of qudits in scalable quantum circuit architectures beyond solid state electron spin qubits.