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SUMMARY:QSE Quantum Seminar - “Can effective descriptions of bosonic sys
 tems be considered complete?”
DTSTART:20250313T120000
DTEND:20250313T133000
DTSTAMP:20260416T125418Z
UID:fb1d74ccf428091dd26d05cddcf36528c3ec8fa2529aa81d56c78318
CATEGORIES:Conferences - Seminars
DESCRIPTION:Ulysse Chabaud\nPlease join us for the QSE Center Quantum S
 eminar with Ulysse Chabaud from École Normale Supérieure in Paris\, 
 who will give the talk "Can effective descriptions of bosonic systems be 
 considered complete?" on Thursday March 13. \nLocation: BS 260.\n\nPizza
 s will be available before the seminar at 12:00. All PhDs\, postdocs\, st
 udents\, and PIs are welcome to join us.\n\nTITLE: "Can effective descrip
 tions of bosonic systems be considered complete?"\n\nABSTRACT: Bosonic sta
 tistics give rise to remarkable phenomena\, from the Hong-Ou-Mandel effect
  to Bose-Einstein condensation\, with applications spanning fundamental sc
 ience to quantum technologies. Modelling bosonic systems relies heavily on
  effective descriptions: typically\, truncating their infinite-dimensional
  state space or restricting their dynamics to a simple class of Hamiltonia
 ns\, such as polynomials of canonical operators. However\, many natural bo
 sonic Hamiltonians do not belong to these simple classes\, and some quantu
 m effects harnessed by bosonic computers inherently require infinite-dimen
 sional spaces. Can we trust that results obtained with such simplifying as
 sumptions capture real effects?\nWe solve this outstanding problem\, showi
 ng that these effective descriptions do correctly capture the physics of b
 osonic systems. Our technical contributions are twofold: firstly\, we prov
 e that any physical bosonic unitary evolution can be accurately approximat
 ed by a finite-dimensional unitary evolution\; secondly\, we show that any
  finite-dimensional unitary evolution can be generated exactly by a bosoni
 c Hamiltonian that is a polynomial of canonical operators. Beyond their fu
 ndamental significance\, our results have implications for classical and q
 uantum simulations of bosonic systems\, provide universal methods for engi
 neering bosonic quantum states and Hamiltonians\, show that polynomial Ham
 iltonians generate universal gate sets for quantum computing over bosonic 
 modes\, and lead to a bosonic Solovay-Kitaev theorem.\n\nJoint work with F
 . Arzani and R. I. Booth: arXiv:2501.13857\n\nBIO: \nUlysse Chabaud is a
  permanent researcher at École Normale Supérieure in Paris\, in the INRI
 A team QAT. Before joining INRIA\, he was a postdoctoral scholar at the In
 stitute for Quantum Information and Matter at Caltech\, and a postdoctora
 l fellow at the Institut de Recherche en Informatique Fondamentale in Pari
 s. He obtained his PhD from Sorbonne Université in 2020. His research int
 erests cover various topics related to quantum information theory\, suc
 h as quantum computing\, quantum cryptography and quantum communication. H
 e investigates the necessary resources for quantum advantages and how the
 y translate to foundational questions\, with an emphasis on bosonic qua
 ntum systems.
LOCATION:BS 260 https://plan.epfl.ch/?room==BS%20260
STATUS:CONFIRMED
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