Dynamic Quantum Operations at Elevated Temperatures Using Hot-Spot Nanoheating of Color Centers.

Abstract

Temperature fluctuations in materials used for quantum networks can give rise to lattice vibrations that detune, dephase, and decrease the lifetimes of embedded quantum defects that function as qubits. Most experiments demonstrating quantum operations have been performed at cryogenic temperatures ranging from milli- to a few kelvin, thereby reducing these adverse effects. However, encouraged by the relatively long lifetimes recently discovered for group IV color centers, we aim to show that subdiffracted heating, i.e., nanoscale thermal "hot spots", produced by a plasmonic transducer can control the resonant behavior of individual qubits. Our analysis, reported over largely unexplored physical dimensions for the nanoheating of qubits, establishes the ability to perform dynamic quantum operations at elevated temperatures via thermally mediated control of two-photon coherence and subsequent photon-number entanglement. As such, color centers raise encouraging prospects for advancing on-chip quantum photonics and elevating solid-state quantum information processing technologies toward higher temperatures.