[seminar] [DANAS] F. Franchini, 10.10. (srijeda) 14h (c.t.), seminar ZTF-a

[Anđelo Samsarov]

    The Frustration in being Odd: area law violation in local systems


     Fabio Franchini
     Ruđer Bošković Institute,
     Division of Theoretical Physics,
     Condensed Matter and Statistical Physics Group




    Datum: srijeda, 10. listopada 2018.
    Vrijeme: 14 sati c.t.
    Mjesto: IRB, predavaona I krila


    Sažetak

   We demonstrate the existence of a new quantum phase of matter that   
  arises in antiferromagnetic spin chains with a weak frustration    
-just one bond in a large chain-. This is the case, for instance,  of   
systems with an odd number of spins with periodic boundary    
conditions. Such new phase is extended, gapless, but not    
relativistic: the low-energy excitations have a quadratic  (Galilean)   
spectrum. Locally, the correlation functions on the  ground state do   
not show significant deviations compared to the  non-frustrated case,   
but correlators involving a number of sites  (or distances) scaling   
like the system size display new  behaviors. In particular, the von   
Neumann entanglement entropy is  found to follow new rules, for which   
neither area law applies,  nor one has a divergence of the entropy   
with the system size.  Such very long-range correlations are novel   
and of potential  technological interest. We display such new phase   
in a few  prototypical chains using numerical simulations and we   
study  analytically the paradigmatic example of the Ising chain.   
Through  these examples we argue that this phase emerges generally in   
  (weakly) frustrated systems with discrete symmetries.
Reference paper
- Salvatore Marco Giampaolo, Flávia Braga Ramos, Fabio Franchini:    
arXiv:1807.07055



Voditelj seminara: Anđelo Samsarov (asamsarov at irb.hr)

http://thphys.irb.hr/Seminar/list.htm
-------------- next part --------------
A non-text attachment was scrubbed...
Name: sem-F.Franchini.pdf
Type: application/pdf
Size: 75182 bytes
Desc: not available
URL: <http://www.phy.pmf.unizg.hr/pipermail/seminar/attachments/20181010/8fbe0257/attachment-0001.pdf>