Experimental Realization of Spinor Slow Light and Demonstration of Its Application

• Main Authors: Lee, Meng-Jung, 李孟融
• Other Authors: Yu, Ite A.
• Format: Others
• Language: en_US
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/78986502967139157538

博士 === 國立清華大學 === 物理系 === 103 === The purpose of the thesis is to study the properties of a double-tripod system theoretically, and then demonstrate experimentally the first measurement of spinor slow light and its new applications of the system via the light storage manipulation. Electromagnetically induced transparency (EIT) is a quantum interference phenomenon, in which a photon at the resonant frequency can pass through a medium perfectly, as if it is completely transparent. Furthermore, the group velocity of photons dramatically reduce due to a large dispersion of refraction index. A typical single- EIT system consists of three energy levels driven by a probe and a coupling field, forming a slow light with single frequency component. We extend the single- configuration by additionally adding an excited state and a ground state to form the five-energy-level double-tripod system, which is driven by six fields made up of two probes and four coupling beams. Due to the six-wave-mixing process in the double-tripod scheme, the energy conversion from one probe field to another is analog to the transformation from spin up to spin down in the spin 1/2 system. We theoretically study the propagation modes of the two-component spinor slow light and compare its properties to those of 3-level and 4-level EIT systems. In double-tripod scheme, the relative phase between coupling fields makes the wave vectors flexible, and results in the transparency for both propagation modes at phase equal to . An oscillation of energy between the two frequency components of the spinor illustrates the interference of the two transparent modes. Moreover, we experimentally observed the oscillation behavior by manipulating the two-photon detunings of both induced atomic ground-state coherences. We store the spinor slow light into the medium and found that the double-tripod system behaves like an interferometer which is feasible for the precision measurement of frequency detuning. We also demonstrate a possible application of a quantum memory or rotator of a two-color qubit. Our work is a milestone in the research of EIT systems and opens a new avenue in the application of quantum optics.