Quantum Manipulation of Nuclear Spin of Ortho-H2 Molecule in Solid Hydrogen

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We carried out the researches to establish a basis for manipulating nuclear-spin quantum-coherence of ortho-hydrogen molecule in solid hydrogen. Simultaneously, we developed a method to manipulate optical processes using optical nanofiber ; it was originally proposed to introduce a strong light into the solid hydrogen.Regarding the ortho-hydrogen project, we developed a highly-stable single-frequency cw laser at 2.4 μm wavelength using doubly-resonant OPO-technique. Ortho-hydrogen infrared transition (v=1-0, J=1-1) was measured systematically. We showed that the transition reveals an ultra-narrow spectral width of 1.6 MHz HWHM. This width is the narrowest width observed just using simple absorption spectroscopy, without using any nonlinear laser-spectroscopic method. Although density of ortho-hydrogen is very low 40 ppm, the peak absorption of 1-cm solid hydrogen crystal reaches to 60% ; it is due to the ultra-narrow spectral feature. We demonstrated also that the vibration-rotation sp … More ectrum splits into three components with splittings of about 10 MHz. The origin of the splitting may be understood due to breaking of magnetic degeneracy of J=1 state into three sublevels via crystal field. The observations have demonstrated that the ortho-hydrogen embedded in solid-parahydrogen is a unique system for realizing quantum coherence control in solid. The observed degeneracy breaking may open a new possibility to realize a new Raman three level scheme without magnetic field.Regarding the nanofiber, we established a method to produce nanofibers with diameter from 1μm to 400 nm with transmission of 80%. We showed theoretically a unique possibility to develop optical processes using nanofibers, very different from those in free space ; a key point is to confine both optical field and atoms/molecules into a submicron space around a nanofiber. We can manipulate single atom/molecule transition just using single photon. Moreover, spontaneous emission of atom/molecule near the nanofiber is strongly modified to emit photons into a guided mode of a nanofiber. We have observed experimentally the unique features of confinement in February of 2006. The observations imply that the nanofiber technique may open a new category of quantum optics. Less