Entanglement and critical phenomena in spin systems under nonuniform fields

CEREZO, M.; CANOSA, N.; LAMAS, C.; ROSSIGNOLI, R.

Buenos Aires

Congreso; Statphys27; 2019

IUPAP

We analyze the entanglement and phase diagram of the exact ground state of finite spin-s arrays with ferromagnetic XXZ couplings under non-uniform fields. It is first shown that these systems can exhibit an exceptionally degenerate multicritical point where all magnetizations plateaus merge and entanglement reaches full range [1], which corresponds to a factorization point. It can arise for a wide variety of field configurations, including standard and sparse alternating fields. It is also shown that under such fields, these systems can exhibit a non-trivial magnetic behavior, with significant magnetization plateaus persistent for large sizes and exhibiting peculiar entanglement properties [1,2]. Finally, it is demonstrated that in these systems the fully aligned