Modular invariance in the gapped XYZ spin-1/2 chain

We show that the elliptic parametrization of the coupling constants of the quantum XYZ spin chain can be analytically extended outside of their natural domain, to cover the whole phase diagram of the model, which is composed of 12 adjacent regions, related to one another by a spin rotation. This ext...

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Bibliographic Details
Main Authors: Ercolessi, Elisa (Author), Evangelisti, Stefano (Author), Franchini, Fabio (Contributor), Ravanini, Francesco (Author)
Other Authors: Massachusetts Institute of Technology. Department of Physics (Contributor)
Format: Article
Language:English
Published: American Physical Society, 2014-08-15T16:12:00Z.
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Online Access:Get fulltext
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100 1 0 |a Ercolessi, Elisa  |e author 
100 1 0 |a Massachusetts Institute of Technology. Department of Physics  |e contributor 
100 1 0 |a Franchini, Fabio  |e contributor 
700 1 0 |a Evangelisti, Stefano  |e author 
700 1 0 |a Franchini, Fabio  |e author 
700 1 0 |a Ravanini, Francesco  |e author 
245 0 0 |a Modular invariance in the gapped XYZ spin-1/2 chain 
260 |b American Physical Society,   |c 2014-08-15T16:12:00Z. 
856 |z Get fulltext  |u http://hdl.handle.net/1721.1/88718 
520 |a We show that the elliptic parametrization of the coupling constants of the quantum XYZ spin chain can be analytically extended outside of their natural domain, to cover the whole phase diagram of the model, which is composed of 12 adjacent regions, related to one another by a spin rotation. This extension is based on the modular properties of the elliptic functions and we show how rotations in parameter space correspond to the double covering PGL(2,Z) of the modular group, implying that the partition function of the XYZ chain is invariant under this group in parameter space, in the same way as a conformal field theory partition function is invariant under the modular group acting in real space. The encoding of the symmetries of the model into the modular properties of the partition function could shed light on the general structure of integrable models. 
546 |a en_US 
655 7 |a Article 
773 |t Physical Review B