Spin-flip-induced superfluidity in a ring of spinful hard-core bosons

The t - J Hamiltonian of the spinful hard-core bosonic ring in the Nagaoka limit is solved. The energy spectrum becomes quantized due to presence of spin, where each energy level corresponds to a cyclic permutation state of the spin chains. The ground state is true ferromagnetic when the ring contains N = 2 and 3 spinful hard-core bosons; for all other N it is a mixture of the ferromagnetic and nonferromagnetic states. This behavior is different from the fermionic ring, where ground state is true ferromagnetic only for N = 3. It is shown that the intrinsic spin-generated gauge fields are analogous to the synthetic gauge fields generated by rotation of either the condensate or the confining potential. It is argued that the low-lying excited levels of the spin-flipped states intrinsically support the superfluidity. Possible ways to experimentally verify these results are also discussed.

Automated summary

This paper solves the t-J Hamiltonian of the spinful hard-core bosonic ring in the Nagaoka limit and finds that the energy spectrum becomes quantized due to the presence of spin. The ground state is true ferromagnetic when the ring contains 2 or 3 spinful hard-core bosons, and a mixture of ferromagnetic and nonferromagnetic states for other cases. The paper also discusses the analogies between intrinsic spin-generated gauge fields and synthetic gauge fields generated by rotation of either the condensate or the confining potential, and explores possible experimental verifications of these results.