Transfer and storage of qubits in the presence of decoherence

TL;DR

This paper investigates how decoherence impacts the transfer and storage of quantum states in hybrid systems, showing that high fidelity is achievable even with relatively short decoherence times, and assesses a hybrid quantum memory system.

Contribution

It provides a theoretical analysis of decoherence effects on quantum state transfer and storage, introducing practical conditions for high fidelity in hybrid quantum systems.

Findings

High transfer fidelity possible with decoherence times less than ten times the transfer time.

Transfer time is approximately half a Rabi period, determined by qubit coupling.

Feasibility of hybrid quantum memory combining atomic and superconducting qubits assessed.

Abstract

The effects of decoherence on the transfer and storage of coherent quantum states in hybrid systems are studied within the Caldeira-Leggett approach. In general, we find that a high transfer fidelity can be achieved even if the decoherence time is less than an order of magnitude larger than the transfer time, which is approximately half a Rabi period and determined by the qubit-qubit coupling strength. Finally, we apply our results to assess the feasibility of a hybrid quantum memory system, comprised of the hyperfine qubit states of an ultracold atomic Bose-Einstein condensate and the flux qubit of a SQUID.