ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT ttk.bme.hu>]

Meghívó

BME Elméleti Fizika Szeminárium,

nov. 18. péntek 10h15,

1111 Budapest, Budafoki út 8., BME F III. magasföldszint 01.,
Elméleti Fizika Tanszék szemináriumi szoba

Vukics András (Wigner FK):
Finite-size scaling and thermodynamic limit in first-order dissipative
phase transition experiments

I present the relatively recent concept of first-order dissipative phase
transitions that can occur in meso- and even microscopic quantum systems.
One of the first examples of this phenomenon was the photon-blockade
breakdown (PBB) effect, that occurs most simply in a coupled system of a
bosonic mode and a qubit, and for which an abstract thermodynamic limit has
been identified [1]. PBB was first observed in a circuit QED system [2],
and the thermodynamic limit could also be modeled on this platform with a
bespoke device [3]. I present this latter set of experiments, together with
the corresponding extensive numerical studies (~ 64 CPU years) performed
with the C++QED simulation framework [4] in an OpenStack cloud environment.
In the second half of the talk I present another first-order DPT that can
be regarded as belonging to the wider category of transmission blockade
breakdown phenomena. This phenomenon has been observed in the rubidium
cold-atom lab in the quantum optics group at the Wigner RCP in a cavity QED
setting in the collective strong coupling regime [5-6].

[1] A. Vukics, A. Dombi, J. M. Fink, P. Domokos, Quantum 3, 150 (2019)
[2] J. M. Fink, A. Dombi, A. Vukics, A. Wallraff, and P. Domokos, Phys.
Rev. X 7, 011012 (2017)
[3] R. Sett, F. Hassani, D. Phan, Sh. Barzanjeh, A. Vukics, and J. M. Fink,
arXiv:2210.14182 [quant-ph]
[4] http://github.com/vukics/cppqed
[5] T. W. Clark, A. Dombi, F. I. B. Williams, Á. Kurkó, J. Fortágh, D.
Nagy, A. Vukics, and P. Domokos, Phys. Rev. A 105, 063712 (2022)
[6] B. Gábor, D. Nagy, A. Dombi, T. W. Clark, F. I. B. Williams, K. V.
Adwaith, A. Vukics, P. Domokos, arXiv:2207.01724 [quant-ph]

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor