A novel quantum memory effect and thermal modulation in graviton-mediated entanglement

TL;DR

This paper tackles the quantum versus classical nature of gravity by modeling quantized gravitational waves interacting with finite‑temperature detectors made of two harmonic oscillators. The authors employ Thermo Field Dynamics to treat detector temperatures separately from a graviton bath and use a Magnus expansion to second order to derive perturbative dynamics, revealing graviton‑induced entanglement and a persistent quantum memory even after the GW drive ends. A key finding is the emergence of a prethermal time‑crystal–like phase and nonlinear thermal amplification that depend on both detector temperature $T$ and graviton temperature $T'$, signaling genuinely quantum gravitational effects. The results yield concrete markers—memory offsets, shifted internal frequencies, and specific entanglement and Rényi‑entropy signatures—that can inform tabletop optomechanical tests and future space/laser interferometry experiments aiming to uncover the quantum nature of gravitons.

Abstract

A central challenge in probing the quantum nature of gravity is to distinguish effects that are genuinely quantum from those that can be explained classically. In this work, we study how quantized gravitational waves interact with thermal quantum systems, modeled as harmonic oscillators. We show that, unlike classical waves, quantized gravitons generate entanglement and leave behind a persistent ``graviton-induced quantum memory'' even after the wave has passed. This effect is further shaped by the presence of thermal noise, which does not simply wash out quantum correlations but can in fact amplify them in distinctive ways. Our analysis reveals clear signatures - such as nonlinear thermal corrections and a prethermal time-crystal-like phase-that cannot arise from any classical treatment. These results identify experimentally relevant markers of gravitons and provide a framework for exploring how finite-temperature environments may help uncover the quantum nature of gravity.

Figures (3)

• Figure 1: $\chi_{\beta'}(\beta)$ versus both the system and graviton bath temperature depicts purity decreases with rise in temperature suggesting temperature enhances entanglement.
• Figure 2: $P^\beta_{1Q}(1.43 \mathrm{s})$ vs $x=\frac{1}{\beta\omega}$ plot for $C^2_\gamma=0.001$: Purity decreases with HO bath temperature favoring entanglement.
• Figure 3: $R(y)$ vs $y=\frac{1}{\beta'\omega_g}$ plot: $R(y)$ increases with graviton bath temperature facilitating entanglement enhancement.