CMSP

Europe/Rome 2019-06-18 11:00:00 2019-06-18 12:00:00 Joint ICTP/SISSA Statistical Physics Seminar: What is Inside a Black Hole We present solutions of the Einstein equations that extend the static Schwarzschild solution in empty space into regions of non-zero energy density $\rho$ and radial pressure $p= w \rho$, where $w$ is a constant equation of state parameter. For simplicity we focus mainly on solutions with constant $\rho$. For $w=0$ we find solutions both with and without a singularity at the origin. Possible applications to galaxies are considered, where we find enhanced velocity rotation curves towards the edge of a galaxy. We propose that our explicit non-singular solution with $w=-1$ describes the interior of a black hole, which is a form of vacuum energy. We verify that its entropy is consistent with the Bekenstein-Hawking entropy, if one assumes the Hawking temperature. We further suggest that this idea can perhaps be applied to the dark energy of the observable universe, if one views the latter as arising from black holes as pockets of vacuum energy. We estimate the average density of such a dark energy to be $\rhobar_\Lambda \approx 10^{-30} g/{\rm cm}^3$. SISSA, Via Bonomea 265 ICTP pio@ictp.it 18 Jun 2019

Europe/Rome 2019-06-25 11:00:00 2019-06-25 11:35:00 Condensed Matter Seminar: Magneto-Electric Coupling through Lattice Distortions We propose a microscopic magneto-electric model in which the coupling between spins and electric dipoles is mediated by lattice distortions. The magnetic sector is described by a spin S=1/2 Heisenberg model coupled directly to the lattice via a  standard spin-Peierls term and indirectly to the electric dipole variables via the distortion of the surrounding electronic clouds. Electric dipoles are described by Ising variables for simplicity, as tunneling quantum effects do not substantially modify the results. We show that the effective magneto-electric coupling which arises due the interconnecting lattice deformations is quite effcient in one-dimensional systems. More precisely, we show using bosonization and extensive DMRG numerical simulations that increasing the magnetic field above the spin Peierls gap, a massive polarization switch-off occurs due to the proliferation of soliton pairs. We also analyze the effect of an external electric field E when the magnetic system is in a gapped (plateau) phase and show that the magnetization can be electrically switched between clearly distint values. We compare these findings with similar effects that have been recently observed in different materials. More general quasi-one-dimensional models and two-dimensional systems are also discussed. We finally propose a possible device (MERAM) based on materials with the behavior described by the present model. ICTP ICTP pio@ictp.it 25 Jun 2019

Europe/Rome 2019-06-25 11:40:00 2019-06-25 12:35:00 Condensed Matter Seminar: Collective and Local Effects in the Driven-Dissipative Dynamics of Many-Body Quantum Systems I will address the emergence of cooperative effects in driven-dissipative many-body quantum systems out of equilibrium, such as superradiant light emission, spin squeezing, phase transitions, and dark states [1-2]. The use of permutational symmetry allows one to efficiently solve the Lindblad dynamics with an exponential reduction in computational resources even accounting for local homogeneous dissipation channels [2]. Using the formalism of Dicke states, it is also possible to extend the study of the driven-dissipative dynamics also to the so-called “ultrastrong” coupling regime of light-matter interaction [2,3]. We crafted a tool in the form of an open-source software, the permutational invariant quantum solver (PIQS) and integrated it in the Quantum Toolbox in Python, QuTiP (www.qutip.org) [4], making it available to the research community for future investigations [5].   [1] Nathan Shammah, Neill Lambert, Franco Nori, and Simone De Liberato, Superradiance with local phase-breaking effects, Phys. Rev. A 96, 023863 (2017). https://arxiv.org/abs/1704.07066   [2] Nathan Shammah, Shahnawaz Ahmed, Neill Lambert, Simone De Liberato, and Franco Nori, Open quantum systems with local and collective incoherent processes: Efficient numerical simulation using permutational invariance, Phys. Rev. A 98, 063815 (2018). https://arxiv.org/abs/1805.05129   [3] Mauro Cirio, Nathan Shammah, Neill Lambert, Simone De Liberato, and Franco Nori, Multielectron ground state electroluminescence, Phys. Rev. Lett. 122, 190403 (2019) https://arxiv.org/abs/1811.08682   [4] J. Robert Johansson, Paul D. Nation, and Franco Nori, QuTiP: An open-source Python framework for the dynamics of open quantum systems, Comp. Phys. Comm. 183, 1760 (2012); QuTiP 2: A Python framework for the dynamics of open quantum systems, ibid. 184, 1234 (2013).   [5] Nathan Shammah and Shahnawaz Ahmed, The rise of open source in quantum physics research, http://blogs.nature.com/onyourwavelength/2019/01/09/the-rise-of-open-source-in-quantum-physics-research/   Biography Dr. Nathan Shammah is a Postdoctoral Researcher in the Theoretical Quantum Physics Laboratory at RIKEN, Wako, Japan. He obtained his Ph.D. from the University of Southampton, U.K., with a thesis on light emission phenomena in solid state systems with flat electronic bands. He is a contributor to QuTiP and is interested in the physics of driven-dissipative many-body quantum systems.  ICTP ICTP pio@ictp.it 25 Jun 2019

Europe/Rome 2019-06-24 08:00:00 2019-06-28 22:00:00 Conference on Nanophononics, Bridging Statistical Physics, Molecular Modeling and Experiments | (smr 3302) To achieve the overarching goal of efficient nanoscale heat management, synergistic multidisciplinary collaborations are required, bridging statistical physics, nonlinear dynamics, molecular modeling, materials science, mechanical engineering, nanodevice fabrication and experiments. The purpose of this conference is to bring together researchers with these different backgrounds to discuss the most recent developments in the field of nanophononics. TOPICS: Heat transport in nonlinear systems Phononic devices Thermal radiation: rectification and amplification Heat conduction and phase change systems Thermal cloaking at the nanoscale SPEAKERS: S. BARONI, SISSA, Trieste, Italy O. BOURGEOIS, Institut Néel, Grenoble, France G. CASATI, University of Insubria, Como, Italy C.-W. CHANG, National Taiwan University K. ESFARJANI, University of Virginia, U.S.A. Z. FAN, Aalto University, Finland V. GIORDANO, Univ. Lyon, France S. LEPRI, CNR, Italy S. MERABIA, ILM Lyon, France M. NOMURA, University of Tokyo, Japan J. ORDONEZ-MIRANDA, CNRS, France L. F. PEREIRA, Univ. Federal do Rio Grande do Norte, Brazil R. RURALI, Materials Science Institute, Barcelona, Spain K. SAITO, Keio University, Yokohama, Japan L. SHI, University of Texas, Austin, U.S.A. S. VOLZ, CNRS – University of Tokyo, Japan C. SEVIK, Eskisehir Technical University, Turkey M. SIMONCELLI, EPFL, Lausanne, Switzerland C. SOTOMAYOR TORRES, ICN2, Barcelona, Spain E. WEIG, University of Constance, Germany I. ZARDO, Univ. Basel, Switzerland GRANTS: A limited number of grants are available to support the attendance of selected participants, with priority given to participants from developing countries. There is no registration fee. ICTP ICTP pio@ictp.it 24 Jun 2019 - 28 Jun 2019

Europe/Rome 2019-07-08 08:00:00 2019-07-12 22:00:00 StatPhys27 | (smr 3308) ICTP supports the participation of scientists from developing countries in STATPHYS27 with a limited number of travel fellowships. For all information on the conference and how to apply, please visit the STATPHYS27 website https://statphys27.df.uba.ar The deadline for applications is March 8, 2019. Program -> https://statphys27.df.uba.ar/program.html   Speakers -> https://statphys27.df.uba.ar/speakers.html   Applications -> https://statphys27.df.uba.ar/registration.html Buenos Aires - Argentina ICTP pio@ictp.it 8 Jul 2019 - 12 Jul 2019

Europe/Rome 2019-07-29 08:00:00 2019-08-01 22:00:00 Conference on Taming Non-Equilibrium Systems: from Quantum Fluctuation to Decoherence | (smr 3316) The workshop aims at reviewing the state-of-the-art in non-equilibrium systems affected by (quantum) fluctuations and decoherence mechanisms bringing together scholars of international calibre active in diverse research communities, such as condensed matter, linear and non-linear optics, cold atoms and quantum information. The workshop aims at reviewing the state-of-the-art and propose developments in the theoretical description and experimental control of decoherence and fluctuations in an ample set of physical contexts. One of the aims of the workshop is to identify similarities and differences between decoherence in model systems, such as optomechanical cavities and open quantum systems, and non-equilibrium phenomena in complex materials. The goal is to set the roadmap to develop a universal view on how decoherence processes and quantum fluctuations govern the non-equilibrium dynamics in different systems. Topics:   Quantum materials Open quantum systems Non equilibrium quantum systems and processes Optomechanical systems Decoherence Cold Atoms Contributed talks: Limited space for contributing talks is available. Poster session: A poster session will be organized. Grants: A limited number of grants are available to support the attendance of selected participants, with priority given to participants from developing countries. There is no registration fee. Sponsor: European Research Council (ERC): INCEPT (Grant Number: 677488) "INhomogenieties and fluctuations in quantum CohErent matter Phases by ultrafast optical Tomography" UfastU (Grant Number: 716648) "Theory of ultra-fast dynamics in correlated multi-band systems" ICTP ICTP pio@ictp.it 29 Jul 2019 - 1 Aug 2019

Europe/Rome 2019-08-12 08:00:00 2019-08-30 22:00:00 College on Energy Transport and Energy Conversion in the Quantum Regime | (smr 3318) The development of quantum technologies is closely connected to the possibility of controlling and manipulating the transport of charge, spin and energy. The aim of this activity is to integrate the communities of Statistical Mechanics, Quantum Information, Cold Atoms and Condensed Matter Physics to understand fundamental aspects of this problem. Topics: Quantum thermoelectricity, theory and experiment Quantum energy dissipation Maxwell Daemons in quantum systems Quantum fluctuation-dissipation relations Quantum thermodynamics in electronic circuits Quantum Floquet engineering Quantum thermodynamics and information theory Transport and thermodynamics in periodically driven electron systems Topological energy conversion Thermal transport and thermoelectricity in topological quantum matter Thermal transport in topological systems Quantum thermal machines Many-body effects in thermal transport Lecturers courses: Giuliano Benenti, Italy Rosario Fazio, Italy Rosa López, Spain Laurens Molenkamp, Germany Juan Parrondo, Spain Jukka Pekola, Finland Anatoli Polkovnikov, USA Ferdinand Schmidt-Kaler, Germany Janine Splettstoeser, Sweden Speakers workshop: Joel Moore, USA Gil Refael, USA Frederick Pierre, France Francesco Giazotto, Italy Christian Schmiegelow, Argentina Christian Glattli, France Clemens Winkelmann, France Heiner Linke, Sweden Sebastian Diehl, Germany Robert Whitney, France Massimiliano Esposito, Luxembourg Raam Uzdin, Israel Ewelina Hankiewicz, Germany David Sanchez, Spain Yuval Gefen, Israel Fabio Taddei, Italy Peter Samuelsson, Sweden Anton Ramsak, Slovenija Michele Campisi, Italy Geraldine Haack, Switzerland Dario Poletti, Singapore Marcos Rigol, USA Grants: A limited number of grants are available to support the attendance of selected participants, with priority given to participants from developing countries. There is no registration fee. ICTP ICTP pio@ictp.it 12 Aug 2019 - 30 Aug 2019