Quantum phenomena in curved spacetime are intriguing research topics that aim to offer hints to the not-yet-known theory of quantum gravity. One famous prediction is the Hawking-Unruh effect, the manifestation of Minkowski vacuum in an accelerating reference frame; a vacuum state in an inertial frame can appear to be a "thermal state" to an accelerating observer! We simulate the radiation by evolving a parametrically driven Bose-Einstein condensate of atoms, which radiates coherent pairs of atoms with opposite momenta. We observe a matterwave field which follows a Boltzmann distribution in local measurements. The extracted temperature and entropy are in excellent agreement with Unruh's predictions. We further observe the long-distance phase coherence and temporal reversibility of emitted matter-waves, hallmarks that distinguish Unruh radiations from classical blackbody radiation. Our results may lead to further insights regarding the nature of quantum dynamics and quantum statistics in a curved spacetime.
Prof. Chin earned his Ph.D in Physics from Stanford University under thesupervision of Steven Chu (Nobel laureate in Physics). He is a professor at the University of Chicago, affiliated with the Department of Physics as well as the Enrico Fermi Institute and the James Franck Institute. Prof. Chin is a very active scientist. He has given many invited talks in international conferences and organized or co-organized many conferences. He has published numerous papers, and is a Thomson Reuters Highly Cited Researcher. Prof. Chin has received many awards for his scientific achievements, including the Overseas Chinese Physics Association's Outstanding Young Researcher Award (2006), the APS I.I. Rabi Prize (2011) and the Bose-Einstein condensation award (2017). He was elected as an American Physical Society Fellow in 2014.