报告内容 摘要 |
In the Stern-Gerlach effect, a magnetic field gradient splits particles into spatially separated paths according to their spin projection. This effect is exploited to creat coherent spatial superpositions for matter-wave interferometry involving two atomic spin states [1], which are readily used to comprise an atom clock. In Einstein's general theory of relativity, time depends locally on gravity; in standard quantum theory, time is global—all clocks “tick” uniformly. We demonstrate a new tool for investigating time in the overlap of these two theories: a self-interfering clock [2]. We prepare the clock in a spatial superposition of quantum wave packets, which evolve coherently along two paths into a stable interference pattern. If we make the clock wave packets “tick” at different rates, to simulate a gravitational time lag, the clock time along each path yields “which path” information, degrading the pattern's visibility. By contrast, in standard interferometry, time cannot yield “which path” information. This proof-of-principle experiment may have implications for the study of time and general relativity and their impact on fundamental effects such as decoherence. |
报告人 简介 |
Dr. Zhou is currently a PBC postdoctoral fellow in the atom chip lab at the Ben-Gurion University of the Negev (BGU), led by Prof. Ron Folman. Prior to joining BGU, he has conducted research in East China Normal University (China), where he received his PhD, National Institute of Standard and Technology (NIST, U.S) and Technical University of Darmstadt (Germany). Zhou’s research direction is quantum optics and atomic physics. His current interest includes atom chips, Bose-Einstein condensation, matter-wave interferometry, quantum entanglement, quantum metrology and fundamental physics in general. |
