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UID:0-990@lptms.universite-paris-saclay.fr
DTSTART;TZID=Europe/Paris:20250114T110000
DTEND;TZID=Europe/Paris:20250114T120000
DTSTAMP:20250106T080858Z
URL:http://www.lptms.universite-paris-saclay.fr/seminars/seminaire-du-lptm
 s-nicolo-beato-mpi-dresden/
SUMMARY:Séminaire du LPTMS : Nicolò Beato (MPIPKS\, Dresden) - Salle des 
 séminaires du FAST et du LPTMS\, bâtiment Pascal n°530 - 14 Jan 25 11:0
 0
DESCRIPTION:Phase transition in quantum control landscapes\n&nbsp\;\nNicol
 ò Beato (MPIPKS\, Dresden)\n&nbsp\;\nControl landscape phase transitions 
 (CLPTs) occur as abrupt changes in the cost function landscape upon varyin
 g a control parameter and can be revealed by non-analytic points in statis
 tical order parameters [1]. A prime example are quantum speed limits (QSL)
  which mark the onset of controllability as the protocol duration is incre
 ased.\nIn this talk\, I present results from recent works introducing anal
 ytical and numerical methods designed to study CLPTs [2-3]:\n(i) Analytica
 l expansions: we lay the foundations of an analytical theory for CLPTs by 
 developing different analytical expansions for the cost function that capt
 ure the behavior of CLPTs with controlled precision\;\n(ii) Stability anal
 ysis: we show that CLPTs can be associated with different types of instabi
 lities of the optimal protocol\; this allows us to explicitly relate CLPTs
  to critical structural rearrangements in the extrema of the control lands
 cape\n(iii) Universality of QSL transition: utilizing path integral method
 s from statistical field theory\, we trace back the critical scaling of th
 e order parameter at the QSL to the properties of the set of optimal proto
 cols\n(iv) Topological CLPTs: we introduce a numerical sampling algorithm 
 designed to explore the set of optimal protocols via homotopic stochastic 
 update rule\; this verifies our analytical predictions and reveals the exi
 stence of a new class of CLPTs\, of topological nature\, associated with s
 harp experimental signatures.\n-\n[1] Phys. Rev. Lett. 122\, 020601\n[2] a
 rXiv:2408.11110\n[3] arXiv:2411.08736
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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