Quantum phases of spin-1 system on 3/4 and 3/5 skewed ladders
| Autor: | Dayasindhu Dey, S. Ramasesha, Sambunath Das, Manoranjan Kumar |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Physics Quantum phase transition Condensed matter physics Strongly Correlated Electrons (cond-mat.str-el) Degenerate energy levels General Physics and Astronomy FOS: Physical sciences 02 engineering and technology Quantum phases 021001 nanoscience & nanotechnology 01 natural sciences Condensed Matter - Strongly Correlated Electrons Spin wave 0103 physical sciences Spin density wave Condensed Matter::Strongly Correlated Electrons Singlet state 0210 nano-technology Ground state Spin-½ |
| Popis: | We study the quantum phase transitions of frustrated antiferromagnetic Heisenberg spin-1 systems on the 3/4 and 3/5 skewed two leg ladder geometries. These systems can be viewed as arising by periodically removing rung bonds from a zigzag ladder. We find that in large systems, the ground state (gs) of the 3/4 ladder switches from a singlet to a magnetic state for $J_1 \ge 1.82$; the gs spin corresponds to ferromagnetic alignment of effective $S = 2$ objects on each unit cell. The gs of antiferromagnetic exchange Heisenberg spin-1 system on a 3/5 skewed ladder is highly frustrated and has spiral spin arrangements. The amplitude of the spin density wave in the 3/5 ladder is significantly larger compared to that in the magnetic state of the 3/4 ladder. The gs of the system switches between singlet state and low spin magnetic states multiple times on tuning $J_1$ in a finite size system. The switching pattern is nonmonotonic as a function of $J_1$, and depends on the system size. It appears to be the consequence of higher $J_1$ favoring higher spin magnetic state and the finite system favoring a standing spin wave. For some specific parameter values, the magnetic gs in the 3/5 system is doubly degenerate in two different mirror symmetry subspaces. This degeneracy leads to spontaneous spin parity and mirror symmetry breaking giving rise to spin current in the gs of the system. 8 pages, 8 figures |
| Databáze: | OpenAIRE |
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