Velocity effects slightly mitigating the quantumness degradation of an Unruh-DeWitt detector

TL;DR

This paper analyzes velocity-dependent responses of Unruh-DeWitt detectors on a planar worldline to quantify how a constant transverse velocity component $w$ influences information degradation from Unruh radiation at high accelerations. Using Gaussian switching and perturbation theory, it derives analytical expressions for transition rates, quantum coherence, and wave–particle duality observables in both non-relativistic and ultra-relativistic velocity regimes, and applies them to an accelerated single-qubit and interferometric circuits. The main finding is that non-relativistic transverse motion ($w\ll1$) slightly mitigates decoherence and the degradation of visibility and which-path information, while ultra-relativistic motion annihilates the detector response, effectively suppressing the Unruh effect; these effects are very small yet conceptually significant. The work provides a theoretical demonstration that detector trajectory, via velocity and acceleration, can subtly shape quantum information processing under relativistic effects, offering a novel perspective on protecting quantumness in high-acceleration settings.

Abstract

In this work, we investigate the velocity effects on information degradation due to the Unruh effect in accelerated quantum systems (with finite interaction time). We consider a detector moving along a spatial trajectory within a two-dimensional plane. The quantum systems studied were: accelerated single-qubit, quantum interferometric circuit, and which-path distinguishability circuit. Thus, for non-relativistic velocity regime, we obtained analytical expressions such as transition rates, quantum coherence, visibility, distinguishability, and the complementarity relation. On the other hand, for the ultra-relativistic velocity regime, we saw that the Unruh effect is suppressed and therefore the detector does not respond in this case. Our findings revealed that velocity effects imply mitigation of information degradation, this interesting behaviors happen because of the composite effect of both velocity and acceleration. The results obtained show that the addition of the non-relativistic, transverse and constant motion of an accelerated detector can play a protective role in quantumness in systems at high accelerations, although the effects are very small.

Figures (5)

• Figure 1: The $\mathcal{Q}^{l^1}_{w}$ as a function of the acceleration parameter $\overline{a}$ for different values of the four-velocity component $w$. We kept the following parameters constant: $\theta = \pi/2$, $\sigma = 10$, and $\lambda = 0.01$.
• Figure 2: The $\mathcal{Q}^{l^1}_{w}$ as a function of the $w$ for different values of the acceleration parameter $\overline{a}$. We kept the following parameters constant: $\theta = \pi/2$, $\sigma = 10$, and $\lambda = 0.01$.
• Figure 3: The $\mathcal{Q}^{l^1}_{w}$ as a function of the polar angle $\theta$ for different values of the four-velocity component $w$. We kept the following parameters constant: $\overline{a} = 100$, $\sigma = 10$, and $\lambda = 0.01$.
• Figure 4: The behavior of $C_{w}$ is presented as a function of the acceleration parameter $\overline{a}$ for distinct values of the four-velocity component $w$. Throughout the analysis, the following parameters were kept fixed: $\sigma = 10$, and $\lambda = 0.01$.
• Figure 5: The $C_{w}$ as a function of $w$ is analyzed for different values of the acceleration parameter $\overline{a}$. The following parameters were held fixed throughout the analysis: $\sigma = 10$, and $\lambda = 0.01$.