For information, please contact Paul Griffin.  Note also the departmental colloquia are typically held on alternate Wednesdays.


Future Seminars

Date Location Speaker Title
 2017-04-28  8.11 Laurent Sanchez-Palencia Spreading of Quantum Correlations in Short- and Long-Range Interacting Systems

Details of Next Seminar

Speaker: Laurent Sanchez-Palencia, Ecole Polytechnique, CNRS, Univ Paris-Saclay)
Date: 28th April 2017
Time: 10am
Location: 8.11
Title: Spreading of Quantum Correlations in Short- and Long-Range Interacting Systems
The out-of-equilibrium dynamics of correlated quantum systems is attracting considerable attention sparked by the emergence of new quantum devices that combine long coherence times, slow dynamics, and precise control of parameters. They concern a variety of systems including ultracold atoms, artificial ion crystals, electronic circuits, spin chains in organic conductors, and quantum photonic systems for instance. One of the most fundamental features of the dynamics of quantum systems is the existence of so-called Lieb-Robinson bounds to the propagation of correlations. Such bounds have fundamental implications on propagation of information, spreading of quantum correlations, and the dynamics of thermalization processes.

Here, we study the dynamics of quantum correlations in various lattice systems using a combination of numerical and analytical many-body approaches. For quantum systems with short-range interactions, our results confirm ballistic spreading of quantum correlations in 1D and 2D Bose-Hubbard models and allow for accurate determination of the cone-like velocity. In dimension higher than two, we show that the correlation pattern is determined by many-body interference effects and that the wave front is characterized by a ballistic spreading within the Manhattan metrics rather than Euclidian metrics, hence producing a square rather than circular correlation front.

In long-range interacting systems, various extensions of the Lieb-Robinson bounds have been proposed. For interactions decaying algebraically in space like 1/R^a in a square lattice of dimension D, universal bounds predict super-ballistic spreading for a > D and no bound for a<=d.
While compatible with those bounds, our results show that
(i)~the quantum speed limit set by Lieb-Robinson bounds is most often not reached,
(ii)~the spreading of quantum correlations is often sub-ballistic,and that it is both
(iii)~ model-dependent and
These conclusions are based on the systematic numerical study of the dynamics of two models characterized by the same universal bounds but that show completely different behaviors and on the study of various observables. These two models, namely the extended Ising and Bose-Hubbard models, are realizable within ultracold atom or ion systems.
The numerics are both qualitatively and quantitatively supported by an analytical approach based on exact dynamics of many-body excitations.

Our results shed new light on the dynamics of quantum correlations in short- and long-range interacting systems. They pave the way to future experimental investigations and application to quantum communications in new engineered quantum devices.

Previous Seminars

2017-03-30 Matthias Sonnleitner,
University of Glasgow
Neglected terms and hidden gems in atom-light interaction
2017-02-16 Irénée Frérot,
ENS de Lyon
Unveiling quantum correlations in many-body systems
2017-02-07 Anton Afanasiev
Institute of Spectroscopy, Russian Academy of Sciences
 From atom optics to light synthesis on a nanometer-scale size
2016-12-09 Tiffany Hart
University of Oxford
Multiple-radiofrequency dressed adiabatic potentials
2016-11-23 Dirk Schuricht
University of Utrecht
Time evolution and relaxation in strongly correlated quantum systems
2016-10-26 Remi Gieger
SYRTE, Observatoire de Paris
Low Frequency Gravitational Wave Detection with Ground Based Atom Interferometer Arrays
2016-06-01 Demosthenes Kivotides
Chemical and Process Engineering
Decay of finite temperature superfluid helium-4 turbulence
2016-04-06 Kevin Weatherill,
Durham University
Thermal Rydberg vapours: quantum optics, terahertz detection and phase transitions
2016-03-02 Waldemar Herr,
University of Hannover
The QUANTUS collaboration: Matter-wave optics in microgravity
2016-02-17 Marzena Szymanska
Non-equilibrium phenomena with quantum fluids of light
2015-11-26 Jose T Mendonça
IPFN/IST, Universidade de Lisboa
Mean-Field Effects In Ultra-Cold Matter:
From Bose-Einstein Condensates To Rydberg Plasmas
2015-11-18 Matthias Keller
University of Sussex
High Resolution Spectroscopy of Molecular Ions
2015-07-07 Peter Schauss,
Local study of quantum transport close to and far away from equilibrium
2015-07-07 Johannes Zeiher,
Many body physics with Rydberg S- and P-states under the microscope
2015-07-07 Alex Glätzle,
Designing Frustrated Quantum Magnets with Laser-Dressed Rydberg Atoms
2015-07-07 Marco Mattioli,
From classical to quantum non-equilibrium dynamics of Rydberg excitations in optical lattices
2015-06-04 Raul Garcia-Patron,
Université Libre de Bruxelles
Ultimate Communication Capacity of Quantum Optical Channels
2015-05-28 Qiang Lin,
Institute of Optics, Zhejiang University
The Investigation of μ-Gal-Level Cold Atom Gravimeter for Field Applications
2015-06-01 Immanuel Bloch,
Probing and Controlling Ultracold Quantum Gases – from Single Atoms to Rydberg Dressing
2015-05-19 Thierry Guillet,
Université de Montpellier
Nitride and ZnO-based photonics: from non-linear optics to novel microlasers
2015-05-18 Alessandro Fedrizzi,
The University of Queensland
On the experimental reality of the wavefunction
2015-04-29 Ben Lanyon,
IQOQI, Innsbruck
 Quantum many-body physics with strings of trapped ions
2015-04-01 Jacob Dunningham,
University of Sussex
Sensing at the quantum limit
2015-03-18 Chris Hooley,
University of St. Andrews
Bragg localisation, Anderson localisation, and the failure of thermalisation: the rich physics of quantum quenches in cold-atom systems
2015-01-27 Markus Greiner,
Harvard University
Measuring Entanglement Entropy in Synthetic Quantum Matter
2015-01-27 Fabio Biancalana,
Interaction between positive and negative frequencies in nonlinear optics
2014-11-19 Torsten Hartmann,
Leibniz Universität Hannover
Towards ultracold polar NaK molecules
2014-11-05 Simon Gardiner,
Durham University & JQC
Bright Matter-Wave Solitons, Interferometry, and Rotational Sensing
2014-09-04 Gangqiang Liu,
University of Pittsburgh
Half-vortex in a Polariton Ring Condensate
2014-09-04 Jonathan Keeling,
University of St. Andrews
Superradiance of cold atoms in optical cavities
2014-08-21 Arnaud Gloppe,
Bidimensional nano-optomechanics and topological backaction in a non-conservative radiation force field
2014-07-23 Gian-Luca Oppo,
CNQO & ICS, Strathclyde
Turbulent, spiral and rogue waves in coherent optical systems
.2014/05/28 Deborah Kane
Macquarie University, Sydney
Nonlinear dynamics of experimental laser systems including complexity analysis
2014-04-09 Mike Charlton
Swansea University
Antihydrogen Trapping and Physics
2014-03-13 Jun Ye JILA Making the world’s best clock
2014-02-20 Charles Adams
Durham University
Strongly interacting photons!
2014-02-19 Jean Dalibard
Exploring Flatland with Cold Atoms (Departmental Colloquium)
2014-02-13 Leo Hollberg
Stanford University
Atoms and Quantum Transitions Probed with Lasers For Real-World Applications (SU2P/SUPA/IMPP Quantum Technologies Colloquium)
2014-02-03 John Kitching
Chip-scale Atomic Devices: Miniature Precision Instruments using Atoms, Lasers and MEMS
2014-01-29 Peter Barker
University College London
From molecules to the mesoscale: Cooling and manipulating complex particles
2014-01-20 Georgios Siviloglou
Massachusetts Institute of Technology
Ultracold rubidium atoms in optical lattices
2014-01-16 Bruno Peaudecerf
Ecole Normale Supérieure, Paris
Feedback loops applied to the measurement and control of light in a cavity
2014-01-15 Giovanni Modugno
LENS / Università di Firenze
Measurement of the mobility edge in 3D Anderson localization
11/12/13 Neal Radwell / Thomas Clark
University of Glasgow
Spatially Dependent EIT from Structured Light
29/11/13 Igor Lesanovsky
University of Nottingham
Dissipative binding and glassy relaxation in Rydberg lattice gases
27/11/13 Danny Segal
Imperial College
Coulomb Crystals and Motional Sideband Spectroscopy of Ca+ Ions in a Penning Trap
13/11/13 Patrick Windpassinger
University of Mainz
Emulating magnetism with ultracold atoms in optical lattices
30/10/13 Jonathan Simon
University of Chicago
Engineering Photonic Topological & Quantum Materials
23/10/13 Charles Wang
University of Aberdeen
Theoretical and Experimental Development of Quantum Sensing Methodology (Departmental Colloquium)
16/10/13 Herwig Ott
TU Kaiserslautern
Quantum Zeno Dynamics with Ultracold Quantum Gases
9/10/13 Jom Luiten Technische Universiteit Eindhoven Cool Beams for Femtosecond Electron Imaging (Departmental Colloquium)
4/10/13 Lauri Toikka
University of Turku
Ring Dark Solitons and Self-Interference in Toroidal Bose-Einstein Condensates
1/10/13 Josh Toomey
Macquarie University
Complexity Analysis of Experimental Nonlinear Laser Systems
25/9/13 Aidan Arnold
University of Strathclyde
Cool things you can do with atoms (Departmental Colloquium)
19/9/13 Quentin Baudouin
Institut Non Linéaire de Nice
Random Lasing in Cold Atoms
29/8/13 Robin Kaiser
Institut Non Linéaire de Nice
Lévy flight of photons in atomic vapours
19/6/13 Saijun Wu
Swansea University
Laser cooling at D1-Line and Prospects of Holographic Single Atom Detection
18/6/13 Nicola Piovella
Università degli Studi di Milano
Cooperative Scattering by Cold Atoms: Theory and Experiments
24/5/13 Andrew Shields
Quantum Communications in the Real World
15/5/13 Florian Schreck
University of Innsbruck
Teaching an old dog new tricks: experiments with quantum degenerate strontium
13/5/13 Jacob Sherson Aarhus University Quantum control: a serious game
1/5/13 Andrew Daley
University of Pittsburgh
Exploring non-equilibrium many-body dynamics with cold atoms (Departmental Colloquium)
22/4/13 David Miller
How to design any linear optical component and how to avoid it (Departmental Colloquium)
15/4/13 Chris Foot
University of Oxford
New techniques for investigating cold/quantum matter
28/3/13 Marina Samoylova
Università degli Studi di Milano
Collective Scattering of Light in High-Finesse Ring Cavities and Optical Lattices
26/3/13 Peter Horak
University of Southampton
Optomechanical effects: From single atoms to optical fibres
18/3/13 Mauro Paternostro
Queen’s University Belfast
A route to quantum effects in mesoscopic systems
6/3/13 Daniele Faccio
Light in moving media (Departmental Colloquium)
27/2/13 Vincent Boyer
University of Birmingham
Quantum optics in the transverse dimension: squeezing the local quantum fluctuations of a light field
13/2/13 Jonathan Leach
Heriot -Watt
How to directly measure a quantum wavefunction
23/1/13 Christophe Salomon
From Ultracold Fermi Gases to Neutron Stars (Departmental Colloquium)
16/1/13 Mike Tarbutt Imperial College Cold molecules as probes of new physics
15/1/13 Andrii Sotnikov
Goethe University Frankfurt
Perspectives in Approaching Quantum Magnetism in Optical Lattices
12/12/12 Ian Walmsley
University of Oxford
Entangbling – quantum correlations in diamond (Departmental Colloquium)
5/12/12 Ifan Hughes Durham University Atom-light interactions at high densities and high magnetic fields
21/11/12 Axel Kuhn
University of Oxford
Photonic Qubits, Qutrits and Ququads in Linear Optical Quantum Circuits
24/10/12 Zoran Hadzibabich
Cambridge University
Quantum-quenched and superheated Bose-condensed atomic gases
17/10/12 Sonja Franke-Arnold
University of Glasgow
The world through a rotating window (Departmental Colloquium)
8/10/12 Rob Scholten
University of Melbourne
Quantum measurement in living cells, and high-coherence electron bunches from cold atoms
26/9/12 Philipp Treutlein
University of Basel
Quantum metrology with a scanning probe atom interferometer
31/8/12 Mark Saffman
University of Wisconsin/Madison
Trapping big atoms in small bottles for quantum computing and nonlinear, atom optics
28/6/12 John Harvey
University of Auckland
Similariton Generation in Optical Fibre Amplifiers
20/6/12 Peter Krüger
University of Nottingham
Atom chips
16/5/12 Dieter Jaksch
University of Oxford
Strongly driven coherent quantum systems
25/4/12 Patrik Öhberg
Heriot-Watt University
Artificial electromagnetism
4/4/12 Mete Atatüre
University of Cambridge
Spins and Photons of Quantum Dots
28/3/12 Matt Jones
Durham University
Spatial correlations in cold Rydberg gases
14/3/12 Robin Kaiser
Institut Non Lineaire de Nice
Coherence effects in light transport : Dicke vs Anderson localization
5/10/11 Elmar Haller
University of Innsbruck
Interacting quantum gases in optical lattice potentials (Departmental Colloquium)