Spin wave and vortex excitations of superfluid 3He-A in parallel-plate geometry.
Quantized vortices with half-integer circulation, which are forbidden from existing in a conventional superfluid because of the single valueness of the wave function, are theoretically predicted to exist in superfluid 3He-A if the order parameters l over and d over form l over perpendicular d over texture. To form the l over perpendicular d over texture, we confined the superfluid between parallel plates with a 12.5 microm gap and applied a magnetic field of H=26.7 mT perpendicular to the plates to take NMR and orient d over perpendicular to l over. NMR spectra exhibit a negative-shift peak which probes that the uniform l over perpendicular d over texture is realized in our cell and show a new satellite signal under rotation. The rotation dependence of the satellite signal is interpreted that a Fréedericksz transition of l over texture is induced by rotation above 1.0 rad/s and vortices start to appear above 1.8 rad/s.
Yamashita
Minoru
M
Department of Physics, Graduate School of Science, Kyoto University, Kyoto 606-8502, Japan.
Izumina
Ken
K
Matsubara
Akira
A
Sasaki
Yutaka
Y
Ishikawa
Osamu
O
Takagi
Takeo
T
Kubota
Minoru
M
Mizusaki
Takao
T