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UID:0-973@lptms.universite-paris-saclay.fr
DTSTART;TZID=Europe/Paris:20240904T134500
DTEND;TZID=Europe/Paris:20240904T144500
DTSTAMP:20240830T081950Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/informal-quantum-
 seminar-shunta-kitahama-tokyo-university/
SUMMARY:Informal Quantum Seminar: Shunta Kitahama (Tokyo University) - Sall
 e des séminaires du FAST et du LPTMS\, bâtiment Pascal n°530 - 4 Sep 24
  13:45
DESCRIPTION:Higher-order exceptional points of many-body unidirectional Hat
 ano-Nelson model\nShunta Kitahama (Tokyo University)\n&nbsp\;\n\nWe study 
 higher-order exceptional points (EP) of the unidirectional Hatano-Nelson m
 odel\, which is one of the simplest non-Hermitian models.\n\nIn the first 
 part\, we introduce the procedure to obtain the Jordan decomposition of th
 e unidirectional Hatano-Nelson model [1]. By identifying the Hamiltonian w
 ith one of the generators of sl₂ algebra\, it is proved that the Jordan 
 decomposition is obtained from polynomials called q-binomial coefficients.
 \n\nIn the second part\, we investigate two physical properties of the uni
 directional Hatano-Nelson model caused by higher-order EP structure: pertu
 rbations and dynamics. First\, we focused on enhanced sensitivity of EP to
  perturbations. The energy level splitting due to perturbations around an 
 n-th order EP exhibits 1/n-th power of the parameters [2]. By introducing 
 a certain perturbation to the EP\, we were able to observe the level split
 ting expected from the Jordan decomposition calculated in [1]. Second\, we
  focused on the dynamics of observables. The dynamics at EPs shows polynom
 ial behavior over time. We calculated the particle number at each site as 
 an observable. As a result\, we found power law dynamics in short time and
  long time dynamics.\n\n[1] S. Kitahama et al.\, J. Stat. Mech. 013101 (20
 24).\n\n[2] H. Hodaei et al.\, Nature 23280 (2017).
CATEGORIES:seminars
LOCATION:Salle des séminaires du FAST et du LPTMS\, bâtiment Pascal n°53
 0\, rue André Riviere\, Orsay\, 91405\, France
X-APPLE-STRUCTURED-LOCATION;VALUE=URI;X-ADDRESS=rue André Riviere\, Orsay\
 , 91405\, France;X-APPLE-RADIUS=100;X-TITLE=Salle des séminaires du FAST 
 et du LPTMS\, bâtiment Pascal n°530:geo:0,0
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