PhD Defense: Tao Peng
Location
Physics : 401
Date & Time
June 18, 2015, 2:00 pm – 4:00 pm
Description
TITLE: High-order Interference of Photons in Thermal State
ABSTRACT: Superposition principle is one of the most challenging principles of quantum theory, especially in the multi-particle situation. In the language of quantum mechanics, the high-order quantum interference of multi-particle is the consequence of a superposition among different yet indistinguishable probability amplitudes, a non-classical entity corresponding to different yet indistinguishable alternative ways of producing a joint-detection event among distant detectors. In this dissertation, we will focus on the study of high-order interference of photons in thermal and pseudo-thermal states. The pseudo-thermal light, consisting of a laser beam and a rotating diffusing ground glass, which is frequently used in the lab, can be modeled as containing a large number of independent and randomly radiated subsources. A large number of sub fields with random phases are then generated from those subsources at random positions and times. A series of experiments were then done by using pseudo-thermal light and a novel detection scheme called Photon-Number Fluctuation Correlation (PNFC) protocol, including a 100% visibility thermal light ghost imaging, the delayed-choice quantum eraser experiment, Popper's experiment, simulation of Bell state and the simulation of 3-photon GHZ state. As we will show in the dissertation, despite the classical feature of the source, the high-order interference of photons in thermal and pseudo-thermal states can only be fully understood by quantum theory due to the nonlocal nature.
ABSTRACT: Superposition principle is one of the most challenging principles of quantum theory, especially in the multi-particle situation. In the language of quantum mechanics, the high-order quantum interference of multi-particle is the consequence of a superposition among different yet indistinguishable probability amplitudes, a non-classical entity corresponding to different yet indistinguishable alternative ways of producing a joint-detection event among distant detectors. In this dissertation, we will focus on the study of high-order interference of photons in thermal and pseudo-thermal states. The pseudo-thermal light, consisting of a laser beam and a rotating diffusing ground glass, which is frequently used in the lab, can be modeled as containing a large number of independent and randomly radiated subsources. A large number of sub fields with random phases are then generated from those subsources at random positions and times. A series of experiments were then done by using pseudo-thermal light and a novel detection scheme called Photon-Number Fluctuation Correlation (PNFC) protocol, including a 100% visibility thermal light ghost imaging, the delayed-choice quantum eraser experiment, Popper's experiment, simulation of Bell state and the simulation of 3-photon GHZ state. As we will show in the dissertation, despite the classical feature of the source, the high-order interference of photons in thermal and pseudo-thermal states can only be fully understood by quantum theory due to the nonlocal nature.
