Quantum Optics with Cold Atoms (Inhibition of Spontaneous Emission, Quantum Zeno Effect, and Bose-Einstein Condensation)

We achieved the Bose-Einstein condensation (BEC) of rubidium atomic gas in 1998which is the first success in Japan and 16th in the world. After the first success of BEC，我们concentrated our interests to coherent properties of matter waves.我们constructed a machu - zehnderinterferometer for matter waves by utilizing Bragg diffraction and successfully观察interference fringes with 100% contrast. This result clarified and confirmed the perfect first ordercoherence of the condensed atoms.我们也可以用一个coherent matter wave amplification withcondensed atoms. A small fraction (about 6%) of BEC atoms was diffracted by A Bragg pulse andnon-resonant laser on the BEC could amplify the matter wave by a factor of 10. We verified that thematter wave phase was conserved through this amplification process using our machzehnderinterferometer for mater aves. the strong atom-photon coupling generated inside high-finesse opticalmicro cavity lets us detect a single atom trajectory in real time. Such a strong coupling is acandidate for trapping a single atom with a single photonwhich is very suitable to realize quantum gate, single photon generator所以on. Several preliminary experimental results已预先报告. However，他们有限地使用longitudinal cavity mode.我们提倡和建立一个novel type ofsingle-atom trapping using a high order transverse mode of the cavity. We observed the signal from单一原子with a fairly good signal to noise ratio. Now we are trying to trap单一原子with a fairly good signal to noise ratio. Now we are trying to trapsingle photons in TEM - 201 - D2 mode of the micro cavity。

We achieved the Bose-Einstein condensation (BEC) of rubidium atomic gas in 1998, which is the first success in Japan and 16th in the world. After the first success of BEC, we concentrated our interests to coherent properties of matter waves. We constructed a Mach-Zehnder interferometer for matter waves by utilizing Bragg diffraction and successfully observed the interference fringes with 100% contrast. This result clarified and confirmed the perfect first order coherence of the condensed atoms. We also performed a coherent matter wave amplification with condensed atoms. A small fraction (about 6%) of BEC atoms was diffracted by a Bragg pulse and non-resonant laser on the BEC could amplify the matter wave by a factor of 10. We verified that the phase of matter wave was conserved through this amplification process using our Mach-Zehnder interferometer for mater waves.The strong atom-photon coupling generated inside high-finesse optical micro cavity lets us detect a single atom trajectory in real time. Such a strong coupling is a candidate for trapping a single atom with a single photon, which is very suitable to realize quantum gate, single photon generator, and so on. Several preliminary experimental results have already been reported. However, they are limited to the use of longitudinal cavity mode. We proposed and constructed a novel type of single-atom trapping using a high-order transverse mode of the cavity. We observed the signal from single atoms with a fairly good signal to noise ratio. Now we are trying to trap single atoms with single photons in TEMィイD201ィエD2 mode of the micro cavity.