Hawking-like effects and Unruh-like effects: toward experiments ?

1996

A comparison between the proposals made to measure Hawking-like effects and the Unruh effect in the laboratory is given at the level of their estimates. No satisfactory scheme exists as yet for their detection.

Foundations of Physics, 2014

There is a persistent state of confusion regarding the nature of the Unruh effect. We will argue that, in contrast to some interpretations thereof, the effect does not represent any novel physics and that, by its very nature, the effect is fundamentally unmeasurable in all experiments of the kind that have been contemplated until now. Also, we discuss what aspects connected with this effect one might consider as possibilities to be explored empirically and what their precise meaning may be regarding the issue at hand. Keywords quantum field theory in curved spacetime • Unruh effect • quantum electrodynamics • accelerated frames

1999

Although the Unruh and Hawking phenomena are commonly linked to field quantization in "accelerated" coordinates or in curved spacetimes, we argue that they are deeply rooted at the classical level. We maintain in particular that these effects should be best understood by considering how the special-relativistic notion of "particle" gets blurred when employed in theories including accelerated observers or in general-relativistic theories, and that this blurring is an instantiation of a more general behavior arising when the principle of equivalence is used to generalize classical or quantum special-relativistic theories to curved spacetimes or accelerated observers. A classical analogue of the Unruh effect, stemming from the non-invariance of the notion of "electromagnetic radiation" as seen by inertial and accelerated observers, is illustrated by means of four gedanken-experimente. The issue of energy balance in the various cases is also briefly discussed. 3 As insightfully discussed by Sciama [3], these phenomena bring together in an intriguing way Einstein's independent legacies of fluctuation theory and relativity.

2011

We show that the Unruh effect can create net quantum entanglement between inertial and accelerated observers depending on the choice of the inertial state. This striking result banishes the extended belief that the Unruh effect can only destroy entanglement and furthermore provides a new and unexpected source for finding experimental evidence of the Unruh and Hawking effects.

Reviews of Modern Physics, 2008

It has been thirty years since the discovery of the Unruh effect. It has played a crucial role in our understanding that the particle content of a field theory is observer dependent. This effect is important in its own right and as a way to understand the phenomenon of particle emission from black holes and cosmological horizons. Here, we review the Unruh effect with particular emphasis to its applications. We also comment on a number of recent developments and discuss some controversies. Effort is also made to clarify what seems to be common misconceptions.

Physics Letters A, 1989

Physical Review Letters, 2011

We compare the response function of an Unruh-DeWitt detector for different space-times and different vacua and show that there is a detailed violation of the equivalence principle. In particular comparing the response of an accelerating detector to a detector at rest in a Schwarzschild space-time we find that both detectors register thermal radiation, but for a given, equivalent acceleration the fixed detector in the Schwarzschild space-time measures a higher temperature. This allows one to locally distinguish the two cases. As one approaches the horizon the two temperatures have the same limit so that the equivalence principle is restored at the horizon.

JETP Letters, 2008

We present simple arguments that detectors moving with constant acceleration (even acceleration for a finite time) should detect particles. The effect is seen to be universal. Moreover, detectors undergoing linear acceleration and uniform, circular motion both detect particles for the same physical reason. We show that if one uses a circularly orbiting electron in a constant external magnetic field as the Unruh-DeWitt detector, then the Unruh effect physically coincides with the experimentally verified Sokolov-Ternov effect.

Physical Review D, 2013

The presence of noncyclic geometric invariant is revealed in all the phenomena where particle generation from vacuum or vacuum condensates appear. Aharonov-Anandan invariants then can help to study such systems and can represent a new tool to be used in order to provide laboratory evidence of phenomena particulary hard to be detected, such as Hawking and Unruh effects and some features of quantum field theory in curved space simulated by some graphene morphologies. It is finally suggested that a very precise quantum thermometer can be built by exploiting geometric invariants properties.

Journal of Physics: Conference Series, 2013

We report on the recent results revealing the presence of geometric invariants in all the phenomena in which vacuum condensates appear and we show that Aharonov-Anandan phase can be used to provide the evidence of phenomena like Hawking and Unruh effects and to test some behavior of quantum field theory in curved space. A very precise quantum thermometer can be also built by using geometric invariants.