We study the ground-state phases of the S = 1/2 Heisenberg quantum antiferromagnet on the spatially anisotropic triangular lattice (SATL) and on the square lattice with up to next-next-nearest-neighbor coupling (the J 1 J2 J3 model), making use of Takahashi's modified spin-wave (MSW) theory supplemented by ordering vector optimization. We compare the MSW results with exact diagonalization and projected-entangled- pair-states calculations, demonstrating their qualitative and quantitative reliability.We find that the MSW theory correctly accounts for strong quantum effects on the ordering vector of the magnetic phases of the models under investigation: in particular, collinear magnetic order is promoted at the expense of non-collinear (spiral) order, and several spiral states that are stable at the classical level disappear from the quantum phase diagram. Moreover, collinear states and non-collinear ones are never connected continuously, but they are separated by parameter regions in which the MSW theory breaks down, signaling the possible appearance of a nonmagnetic ground state. In the case of the SATL, a large breakdown region appears also for weak couplings between the chains composing the lattice, suggesting the possible occurrence of a large non-magnetic region continuously connected with the spin-liquid state of the uncoupled chains. This shows that the MSW theory is-despite its apparent simplicity-a versatile tool for finding candidate regions in the case of spin-liquid phases, which are among prime targets for relevant quantum simulations. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.

Modified spin-wave theory with ordering vector optimization: Spatially anisotropic triangular lattice and J1 J2 J3 model with Heisenberg interactions / Hauke, Philipp; Roscilde, Tommaso; Murg, Valentin; Cirac, J. Ignacio; Schmied, Roman. - In: NEW JOURNAL OF PHYSICS. - ISSN 1367-2630. - ELETTRONICO. - 13:7(2011), pp. 075017.1-075017.29. [10.1088/1367-2630/13/7/075017]

Modified spin-wave theory with ordering vector optimization: Spatially anisotropic triangular lattice and J1 J2 J3 model with Heisenberg interactions

Hauke, Philipp;
2011-01-01

Abstract

We study the ground-state phases of the S = 1/2 Heisenberg quantum antiferromagnet on the spatially anisotropic triangular lattice (SATL) and on the square lattice with up to next-next-nearest-neighbor coupling (the J 1 J2 J3 model), making use of Takahashi's modified spin-wave (MSW) theory supplemented by ordering vector optimization. We compare the MSW results with exact diagonalization and projected-entangled- pair-states calculations, demonstrating their qualitative and quantitative reliability.We find that the MSW theory correctly accounts for strong quantum effects on the ordering vector of the magnetic phases of the models under investigation: in particular, collinear magnetic order is promoted at the expense of non-collinear (spiral) order, and several spiral states that are stable at the classical level disappear from the quantum phase diagram. Moreover, collinear states and non-collinear ones are never connected continuously, but they are separated by parameter regions in which the MSW theory breaks down, signaling the possible appearance of a nonmagnetic ground state. In the case of the SATL, a large breakdown region appears also for weak couplings between the chains composing the lattice, suggesting the possible occurrence of a large non-magnetic region continuously connected with the spin-liquid state of the uncoupled chains. This shows that the MSW theory is-despite its apparent simplicity-a versatile tool for finding candidate regions in the case of spin-liquid phases, which are among prime targets for relevant quantum simulations. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft.
2011
7
Hauke, Philipp; Roscilde, Tommaso; Murg, Valentin; Cirac, J. Ignacio; Schmied, Roman
Modified spin-wave theory with ordering vector optimization: Spatially anisotropic triangular lattice and J1 J2 J3 model with Heisenberg interactions / Hauke, Philipp; Roscilde, Tommaso; Murg, Valentin; Cirac, J. Ignacio; Schmied, Roman. - In: NEW JOURNAL OF PHYSICS. - ISSN 1367-2630. - ELETTRONICO. - 13:7(2011), pp. 075017.1-075017.29. [10.1088/1367-2630/13/7/075017]
File in questo prodotto:
File Dimensione Formato  
Murg_Modified spin-wave theory with ordering vector.pdf

accesso aperto

Tipologia: Versione editoriale (Publisher’s layout)
Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 3.12 MB
Formato Adobe PDF
3.12 MB Adobe PDF Visualizza/Apri

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11572/256423
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 37
  • ???jsp.display-item.citation.isi??? 35
social impact