The Berry phase from the entanglement of future and past light cones: detecting the timelike Unruh effect

TL;DR

This paper proposes a new method to detect the timelike Unruh effect using a simple $$-system, offering an experimentally feasible alternative to traditional detectors that require extreme accelerations.

Contribution

It introduces a novel approach to observe the timelike Unruh effect through geometric phase in a $$-system, bypassing the need for high accelerations.

Findings

The geometric phase from timelike entanglement can be measured in a $$-system.

Current technology can detect the timelike Unruh effect with a stationary, time-dependent $$-system.

The approach provides an alternative to the Unruh-deWitt detector for observing the effect.

Abstract

The Unruh effect can not only arise out of the entanglement between modes of left and right Rindler wedges, but also between modes of future and past light cones. We explore the geometric phase resulting from this timelike entanglement between the future and past, showing that it can be captured in a simple $\Lambda$-system. This provides an alternative paradigm to the Unruh-deWitt detector. The Unruh effect has not been experimentally verified because the accelerations needed to excite a response from Unruh-deWitt detectors are prohibitively large. We demonstrate that a stationary but time-dependent $\Lambda$-system detects the timelike Unruh effect with current technology.