Vortex-Lattice Phases of Superfluid 3He in Rapid Rotation

Superfluid ³He in the angular velocity of 0.01Ω_c2<=Ω<=Ω_c2 is studied theoretically, where Ω_c2 is the upper critical field of order \(1-T/T_c\)×10⁷ rad/s. Five different phases have been found in the pressure- Ω plane. Especially, it is shown that the A-phase-core vortex experimentally found in the B phase originates from Schopohl's polar state at Ω_c2 via an A-phase mixed-twist lattice with polar cores and the normal-core lattice of Ohmi, Tsuneto, and Fujita [Prog. Theor. Phys. 70, 647 (1983)].