[seminar] [DANAS] H. Buljan, 12.4. (srijeda) 14h (c.t.), seminar ZTF-a

[Anđelo Samsarov]

        SEMINAR  TEORIJSKE  FIZIKE


    (Zajednički seminari Fizičkog odsjeka PMF-a te Zavoda za teorijsku
     fiziku i Zavoda za eksperimentalnu fiziku IRB-a)

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    Weyl semimetals in 3D optical lattices, and synthetic gauge fields
             in strongly interacting 1D Bose gases


    Hrvoje Buljan
    Department of Physics, Faculty of Science,
    University of Zagreb


    Datum:  srijeda, 12. travnja 2017.
    Vrijeme: 14 sati c.t.
    Mjesto: IRB, predavaona I krila


   Sažetak:

   We discuss two important directions of research of synthetic  
topological quantum matter [1]: (i) topological phases in 3D optical  
lattices, more specifically Weyl semimetals in ultracold atomic gases  
[2], and (ii) strongly interacting Bose gases in synthetic gauge  
fields [3]. Interacting Bose gases in synthetic magnetic fields [1]  
hold great potential for discovering and exploring novel topological  
states of matter [4], in a similar fashion as the fractional quantum  
Hall effect for electrons in strong magnetic fields. Here we  
investigate laser assisted tunneling in a strongly interacting  
one-dimensional Bose gas [3] (the Tonks-Girardeau gas [5]) in optical  
lattices. We find that the stroboscopic dynamics of the  
Tonks-Girardeau gas in a continuous Wannier-Stark-ladder potential,  
supplemented with laser assisted tunneling, effectively realizes the  
ground state of one-dimensional hardcore bosons in a discrete lattice  
[6] with nontrivial hopping phases. Next, we show that, in  
three-dimensional optical lattices, laser assisted tunneling can be  
used for realizing a Hamiltonian with Weyl points [3]. Weyl points are  
synthetic magnetic monopoles that exhibit a robust, three-dimensional  
linear dispersion, identical to the energy-momentum relation for  
relativistic Weyl fermions [3], which are not yet discovered in  
particle physics. Relation to analogous studies in optics will be  
mentioned [8].

[1] N. Goldman, G. Juzeliunas, P. Ohberg, I. B. Spielman, Rep. Prog.  
Phys. 77, 126401 (2014).
[2] Tena Dubček, Colin J. Kennedy, Ling Lu, Wolfgang Ketterle, Marin  
Soljačić, Hrvoje Buljan, Weyl points in three-dimensional optical  
lattices: Synthetic magnetic monopoles in momentum space, Phys. Rev.  
Lett. 114, 225301 (2015).
[3] Karlo Lelas, Nikola Drpić, Tena Dubček, Dario Jukić, Robert Pezer,  
and Hrvoje Buljan, Laser assisted tunneling in a Tonks-Girardeau gas,  
New J. of Phys. 18, 095002 (2016).
[4] X. Chen, Z.-C. Gu, Z.-X. Liu, X.-G. Wen, arXiv:1301.0861  
[cond-mat.str-el]; Science 338, 1604 (2012).
[5] M. Girardeau, J. Math. Phys. 1, 516 (1960).
[6] M. Rigol and A. Muramatsu, Phys. Rev. Lett. 93, 230404 (2004).
[7] R. Pezer and H. Buljan, Phys. Rev. Lett. 98, 240403 (2007).
[8] Jorge Bravo-Abad, Ling Lu, Liang Fu, Hrvoje Buljan and Marin  
Soljačić, Weyl points in photonic-crystal superlattices, 2D Mater. 2,  
034013 (2015); Tena Dubček, Karlo Lelas, Dario Jukić, Robert Pezer,  
Marin Soljačić and Hrvoje Buljan, The Harper–Hofstadter Hamiltonian  
and conical diffraction in photonic lattices with grating assisted  
tunneling, New J. Phys. 17, 125002 (2015).


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

http://thphys.irb.hr/Seminar/list.htm
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