Magnetism of one-dimensional strongly repulsive spin-1 bosons with antiferromagneticspin-exchange interaction

摘要

We investigate magnetism and quantum phase transitions in a one-dimensional system of integrable spin- Ibosons with strongly repulsive density-density interaction and antiferromagnetic spin-exchange interaction viathe thermodynamic Bethe ansatz method. At zero temperature, the system exhibits three quantum phases: (i) asinglet phase of boson pairs when the external magnetic field H is less than the lower critical field H_(c1);(ii) aferromagnetic phase of atoms in the hyperfine state |F= 1 , m_F= 1)when the external magnetic field exceedsthe upper critical field H_(c2);and (iii) a mixed phase of singlet pairs unpaired atoms in the intermediateregion H_(c1)