Dresden 2014 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 4: Low-Dimensional Systems: 1D - Theory

TT 4.5: Vortrag

Montag, 31. März 2014, 10:30–10:45, HSZ 201

Effective gauge field description for the bilinear-biquadratic spin-one chain — •Shijie Hu¹, Ari M. Turner², Karlo Penc^3,4, and Frank Pollmann¹ — ¹Max-Planck-Institut fuer Physik komplexer Systeme, 01187 Dresden, Germany — ²University of Amsterdam, 1090 GL Amsterdam, The Netherlands — ³Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, H-1525 Budapest, P.O.B. 49, Hungary — ⁴Department of Physics, Budapest University of Technology and Economics, 1111 Budapest, Hungary

We study the one-dimensional bilinear-biquadratic spin-one model. For this model, the possible existence of a nematic phase between a dimerized and a ferromagnetic phase has been debated. We present strong evidence for the absence of such an intermediate phase by comparing prediction of an effective gauge theory with the results of large scale density-matrix renormalization group (DMRG) simulations. In particular we compare the scaling of the correlations length and the dimerization strength obtained from the gauge theory with the DMRG results. It is found that quantum fluctuations melt the nematic order and stabilize a gapped, dimerized phase which persists all the way to the edge of the ferromagnetic phase. We furthermore discuss the multiplet structure found in the entanglement spectrum of the ground state wave functions.