Towards Realizing a Quantum Memory for a Superconducting Qubit: Storage and Retrieval of quantum states

TL;DR

This paper demonstrates a hybrid quantum system combining a superconducting flux qubit with a nitrogen-vacancy center ensemble in diamond, enabling storage, retrieval, and entanglement of quantum states, advancing quantum memory development.

Contribution

The work introduces a functional hybrid quantum memory system with demonstrated state transfer, storage, retrieval, and entanglement preservation between superconducting qubits and NV centers.

Findings

Successful transfer of quantum states from flux qubit to NV ensemble

Storage and retrieval of quantum information demonstrated

Entanglement between processor and memory preserved

Abstract

We have built a hybrid system composed of a superconducting flux qubit (the processor) and an ensemble of nitrogen-vacancy centers in diamond (the memory) that can be directly coupled to one another and demonstrated how information can be transferred from the flux qubit to the memory, stored and subsequently retrieved. We have established the coherence properties of the memory, and succeeded in creating an entangled state between the processor and memory, demonstrating how the entangled state's coherence is preserved. Our results are a significant step towards using an electron spin ensemble as a quantum memory for superconducting qubits.