Temperature study of Rydberg exciton optical properties in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msub><mml:mi>Cu</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">O</mml:mi></mml:mrow></mml:math>
Dongyeon Daniel Kang, Aaron Gross, HeeBong Yang, Yusuke Morita, K. S. Choi, Kosuke Yoshioka, Na Young Kim
Abstract
Rydberg excitons in ${\mathrm{Cu}}_{2}\mathrm{O}$ 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 ${\mathrm{Cu}}_{2}\mathrm{O}$ 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 ($\ensuremath{\sim}80\phantom{\rule{0.16em}{0ex}}\mathrm{K}$), 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 ${\mathrm{Cu}}_{2}\mathrm{O}$.