Temperature Study of Rydberg Exciton Optical Properties in Cu2O

TL;DR

This study investigates how Rydberg exciton resonances in Cu2O change with temperature, showing potential for high-temperature quantum information applications by maintaining excitonic properties up to 100 K.

Contribution

It provides the first detailed analysis of temperature effects on Rydberg excitons in Cu2O, demonstrating their viability at temperatures above liquid nitrogen boiling point.

Findings

Rydberg exciton states are observable up to 100 K.

Standard scaling laws for excitons hold at elevated temperatures.

High-temperature Rydberg exciton properties support quantum information processing.

Abstract

Rydberg excitons in Cu2O can be an emergent platform for solid-state quantum information processing by utilizing the exaggerated properties of high-lying excited states within the material. To develop practical quantum systems, high-temperature operation is desirable. Here, we study the temperature-dependence of the yellow and green Rydberg exciton resonances in a thin Cu2O crystal via broad-band phonon-assisted absorption spectra between 4 K and 100 K. At 4 K, we can identify the principal quantum number n = 11 yellow and n = 4 green Rydberg exciton states, beyond which we are limited by the spectral resolution of standard absorption techniques. Above liquid nitrogen boiling temperature (~80 K), the n = 6 yellow and n = 4 green Rydberg exciton states are readily captured and higher-temperature yellow Rydberg exciton optical properties still exhibit the standard scaling laws seen at low temperatures. This promising result lays the groundwork for a new route to build a high-temperature Rydberg quantum information processing architecture with solid-state Cu2O.