We investigate the non-equilibrium steady state (NESS) in an open quantum XXZ chain attached at the ends to polarization baths with unequal polarizations. Using the general theory developed in Popkov (2017 Phys. Rev. A 95 052131), we show that in the critical XXZ |∆| < 1 easy plane case, the steady current in large systems under strong driving shows resonance-like behaviour, by an infinitesimal change of the spin chain anisotropy or other parameters. Alternatively, by fine tuning the system parameters and varying the boundary dissipation strength, we observe a change of the NESS current from diffusive (of order 1/N , for small dissipation strength) to ballistic regime (of order 1, for large dissipation strength). This drastic change results from an accompanying structural change of the NESS, which becomes a pure spin- helix state characterized by a winding number which is proportional to the system size. We calculate the critical dissipation strength needed to observe this surprising effect.
Spin-helix states in the XXZ spin chain with strong boundary dissipation / Popkov, Vladislav; Schmidt, Johannes; Presilla, Carlo. - In: JOURNAL OF PHYSICS. A, MATHEMATICAL AND THEORETICAL. - ISSN 1751-8113. - STAMPA. - 50:43(2017), p. 435302. [10.1088/1751-8121/aa86cb]
Spin-helix states in the XXZ spin chain with strong boundary dissipation
Presilla, Carlo
2017
Abstract
We investigate the non-equilibrium steady state (NESS) in an open quantum XXZ chain attached at the ends to polarization baths with unequal polarizations. Using the general theory developed in Popkov (2017 Phys. Rev. A 95 052131), we show that in the critical XXZ |∆| < 1 easy plane case, the steady current in large systems under strong driving shows resonance-like behaviour, by an infinitesimal change of the spin chain anisotropy or other parameters. Alternatively, by fine tuning the system parameters and varying the boundary dissipation strength, we observe a change of the NESS current from diffusive (of order 1/N , for small dissipation strength) to ballistic regime (of order 1, for large dissipation strength). This drastic change results from an accompanying structural change of the NESS, which becomes a pure spin- helix state characterized by a winding number which is proportional to the system size. We calculate the critical dissipation strength needed to observe this surprising effect.File | Dimensione | Formato | |
---|---|---|---|
Presilla_Spin-helix-states.pdf
solo gestori archivio
Tipologia:
Versione editoriale (versione pubblicata con il layout dell'editore)
Licenza:
Tutti i diritti riservati (All rights reserved)
Dimensione
3.72 MB
Formato
Adobe PDF
|
3.72 MB | Adobe PDF | Contatta l'autore |
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.