BEGIN:VCALENDAR VERSION:2.0 PRODID:-//Nonequilibrium Quantum Workshop NQW - ECPv6.14.2//NONSGML v1.0//EN CALSCALE:GREGORIAN METHOD:PUBLISH X-WR-CALNAME:Nonequilibrium Quantum Workshop NQW X-ORIGINAL-URL:https://nqw.ijs.si X-WR-CALDESC:Events for Nonequilibrium Quantum Workshop NQW REFRESH-INTERVAL;VALUE=DURATION:PT1H X-Robots-Tag:noindex X-PUBLISHED-TTL:PT1H BEGIN:VTIMEZONE TZID:Europe/Ljubljana BEGIN:DAYLIGHT TZOFFSETFROM:+0100 TZOFFSETTO:+0200 TZNAME:CEST DTSTART:20210328T010000 END:DAYLIGHT BEGIN:STANDARD TZOFFSETFROM:+0200 TZOFFSETTO:+0100 TZNAME:CET DTSTART:20211031T010000 END:STANDARD END:VTIMEZONE BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T085900 DTEND;TZID=Europe/Ljubljana:20211214T101400 DTSTAMP:20260809T181333 CREATED:20211207T113320Z LAST-MODIFIED:20211207T120240Z UID:2150-1639472340-1639476840@nqw.ijs.si SUMMARY:Chair: Denis Golež DESCRIPTION: URL:https://nqw.ijs.si/event/chair-denis-golez/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T090000 DTEND;TZID=Europe/Ljubljana:20211214T092500 DTSTAMP:20260809T181333 CREATED:20211201T213346Z LAST-MODIFIED:20211215T150724Z UID:1906-1639472400-1639473900@nqw.ijs.si SUMMARY:Philipp Werner: Nonthermal electronic orders DESCRIPTION:P. Werner\,1 Y. Murakami2 \n1University of Fribourg\, 1700 Fribourg\, Switzerland \n2Tokyo Institute of Technology\, Meguro\, Tokyo 152-8551\, Japan \nRecent experiments and theoretical studies suggest that electronic orders such as superconductivity or excitonic insulator phases can be realized in highly nonthermal systems. In this talk\, I will discuss some examples which have been demonstrated in nonequilibrium dynamical mean field theory simulations of Hubbard-type models. After briefly reviewing results for nonthermal magnetic order and the eta-pairing state in photo-doped Mott insulators\, I will discuss in more detail two recent studies on nonthermal excitonic order in a two-orbital Hubbard model with Hund coupling and crystal field splitting [1] and on a nonthermal form of composite order (or odd-frequency orbital order) in a three-orbital Hubbard model which is relevant for the description of A3C60 [2]. The excitonic insulator study reveals a new entropy-trapping mechanism for nonthermal orders\, while the fulleride example demonstrates a nonthermal electronic order which is stabilized by the kinetic energy of the photo-excited charge carriers. \n\nP. Werner and Y. Murakami\, Phys. Rev. B 102\, 241103(R) (2020).\nP. Werner and Y. Murakami\, Phys. Rev. B 104\, L201101 (2021).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/philipp-werner-nonthermal-electronic-orders/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T092500 DTEND;TZID=Europe/Ljubljana:20211214T095000 DTSTAMP:20260809T181333 CREATED:20211201T213807Z LAST-MODIFIED:20211215T150814Z UID:1927-1639473900-1639475400@nqw.ijs.si SUMMARY:Salvatore R. Manmana: Photoinduced spinful excitons in Hubbard systems with magnetic superstructures DESCRIPTION:C. Meyer1 and S.R. Manmana1 \n1Institute for Theoretical Physics\, University of Göttingen\,Friedrich-Hund-Platz 1\, D-37077 Göttingen\, Germany \nThe possibility to form excitons in photo-illuminated correlated materials is central from fundamental and application oriented perspectives. We show how the interplay of electron-electron interactions and a magnetic superstructure leads to the formation of a peculiar spinful exciton\, which can be detected in ARPES-type experiments and optical measurements. We study this by using matrix product states (MPS) to compute the time evolution of single-particle spectral functions and of the optical conductivity following an electron-hole excitation in a class of one-dimensional correlated band-insulators\, simulated by Hubbard models with on-site interactions and alternating local magnetic fields. An excitation in only one specific spin direction leads to an additional band in the gap region of the spectral function only in the spin direction unaffected by the excitation and to an additional peak in the optical conductivity. Recombination of the excitation happens on much longer time scales than the ones amenable to MPS. We discuss implications for experimental studies in correlated insulator systems. \n\nC. Meyer and S.R. Manmana\, arXiv:2109.07037 (2021)\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/salvatore-r-manmana-photoinduced-spinful-excitons-in-hubbard-systems-with-magnetic-superstructures/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T095000 DTEND;TZID=Europe/Ljubljana:20211214T101500 DTSTAMP:20260809T181333 CREATED:20211201T213808Z LAST-MODIFIED:20211215T150834Z UID:1928-1639475400-1639476900@nqw.ijs.si SUMMARY:Masud Haque: Assigning temperatures to many-body eigenstates DESCRIPTION:Watch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/masud-haque-assigning-temperatures-to-many-body-eigenstates/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T101500 DTEND;TZID=Europe/Ljubljana:20211214T104500 DTSTAMP:20260809T181333 CREATED:20211201T212913Z LAST-MODIFIED:20211201T212913Z UID:1886-1639476900-1639478700@nqw.ijs.si SUMMARY:Coffee break DESCRIPTION: URL:https://nqw.ijs.si/event/coffee-break/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T104400 DTEND;TZID=Europe/Ljubljana:20211214T115900 DTSTAMP:20260809T181333 CREATED:20211207T113502Z LAST-MODIFIED:20211207T120257Z UID:2154-1639478640-1639483140@nqw.ijs.si SUMMARY:Chair: Jure Demsar DESCRIPTION: URL:https://nqw.ijs.si/event/chair-jure-demsar/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T104500 DTEND;TZID=Europe/Ljubljana:20211214T111000 DTSTAMP:20260809T181333 CREATED:20211201T213808Z LAST-MODIFIED:20211215T150931Z UID:1929-1639478700-1639480200@nqw.ijs.si SUMMARY:Hermann Durr: Ultrafast manipulation of the NiO antiferromagnetic order via sub-gap optical excitation DESCRIPTION:X. Wang\,1 D. Turenne\,1 V. Shokeen\,1 A. Yaroslavtsev\,1 I. Vaskivskyi\,2 O. Grånäs\,1 R. Y. Engel\,3 J. Schunk\,3 S. Dziarzhytski\,3 G. Brenner\,3 R.-P. Wang\,3 M. Kuhlmann\,3 F. Kuschewski\,3 M. Beye\,3 W. Bronsch\,4 F. Parmigiani\,4 C. Schüssler-Langheine\,5 A. Steyervoyedov\,6 S. S. P. Parkin\,6 O. Eriksson\,1 H. A. Dürr1 \n1Department of Physics and Astronomy\, Uppsala University\, 751 20 Uppsala\, Sweden. \n2Deutsches Elektronen Synchrotron\, 22607 Hamburg\, Germany. \n3Complex Matter Department\, Jozef Stefan Institute\, Ljubljana\, Slovenia. \n4Elettra Sincrotrone Trieste S.C.p.A. Strada Statale 14 – km 163.5 in AREA Science Park 34149 Basovizza\, Trieste\, Italy. \n5Helmholtz-Center Berlin für Materialien und Energie\, Hahn-Meitner-Platz 1\, 1419 Berlin\, Germany. \n6Max-Planck Institut für Mikrostrukturphysik\, Weinberg 2\, Halle\, Germany. \nWide-band-gap insulators such as NiO offer the exciting prospect of coherently manipulating electronic correlations with strong optical fields [1]. Contrary to metals where rapid dephasing of optical excitations via electronic processes occurs\, the sub-gap excitation in charge-transfer insulators has been shown to couple to low-energy bosonic\, probably phonon\, excitations [2]. Here we use the prototypical charge-transfer insulator NiO to demonstrate that sub-gap excitation leads to a renormalized NiO band-gap in combination with a significant reduction of the antiferromagnetic order. We employ element-specific x-ray absorption spectroscopy at the FLASH free electron laser [3] to demonstrate the reduction of the upper band-edge at the O 1s-2p core-valence resonance whereas the antiferromagnetic order is probed via x-ray magnetic linear dichroism (XMLD) at the Ni 2p-3d resonance. Comparing the transient XMLD spectral lineshape to ground-state measurements [4] allows us to extract a spin temperature rise of more than 60 K for time delays longer than 400 fs. This is accompanied by a band-gap reduction. Before 400 fs a non-equilibrium state is formed characterized by O 2p mid-gap states. We will discuss these results in terms of a transient Ni-O charge transfer during the optical driving field. The energetic proximity of our 800 nm excitation wavelength to phonon-assisted NiO d-d transitions facilitates the bosonic dressing of the laser field. Finally\, laser-excited phonons [5] couple to magnons on a ~400 fs timescale enabling the quenching of the NiO magnetic order [6]. \nReferences: \n\nN. Tancogne-Dejean\, M. A. Sentef\, A. Rubio\, Phys. Rev. Lett. 121\, 097402 (2018).\nF. Novelli\, et al. Nature Commun. 5:5112 (2014).\nR. Y. Engel\, et al. Appl. Sci. 10\, 6947 (2020).\nD. Alders\, et al. Phys. Rev. B 57\, 11623 (1998).\nY. L. Windsor\, et al. Phys. Rev. Lett. 126\, 147202 (2021).\nP. Maldonado\, Y. O. Kvashnin\, Phys. Rev. B 100\, 014430 (2019).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/hermann-durr-ultrafast-manipulation-of-the-nio-antiferromagnetic-order-via-sub-gap-optical-excitation/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T111000 DTEND;TZID=Europe/Ljubljana:20211214T113500 DTSTAMP:20260809T181333 CREATED:20211201T213808Z LAST-MODIFIED:20211215T150953Z UID:1930-1639480200-1639481700@nqw.ijs.si SUMMARY:Urs Staub: Resonant excitations of spins\, orbitals and lattice probed by x-rays DESCRIPTION:Urs Staub1 \n1Swiss Light Source\, Paul Scherrer Institute\, 4232 Villigen PSI\, Switzerland \nResults will be presented of how the spins\, the orbitals and the lattice react to phase stable excitations of low energy phonons\, electromagnons or orbitals. Examples will cover soft mode driving of the ferroelectric mode in SrTiO3\, [1] electromagnon excitation in hexaferrites and orbital excitation in magnetically frustrated Tb2Ti2O7. These ultrafast changes caused by the excitations are probed by resonant and non-resonant X-ray diffraction to obtain the lattice the spin and/or the orbital dynamics. Recent results from SwissFEL will be presented. \n\nM. Kozina et al.\, Nat. Phys. 15\, 387 (2019).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/urs-staub-resonant-excitations-of-spins-orbitals-and-lattice-probed-by-x-rays/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T113500 DTEND;TZID=Europe/Ljubljana:20211214T120000 DTSTAMP:20260809T181333 CREATED:20211201T213808Z LAST-MODIFIED:20211215T151020Z UID:1931-1639481700-1639483200@nqw.ijs.si SUMMARY:Claude Monney: Transient Enhancement of the Ferroelectricity in the Rashba Semiconductor α-GeTe DESCRIPTION:G. Kremer\,1 C.W. Nicholson\,1 L. Nicolaï\,2 J. Maklar\,3 C. Silva\,3 R. Ernstorfer\,3 L. Rettig\,3 J.H. Dil\,4\,5 J. Minár\,2 G. Springholz\,6 J. Krempaský\,5 and C. Monney1 \n1Département de Physique and Fribourg Center for Nanomaterials\, Université de Fribourg\, CH-1700 Fribourg\, Switzerland \n2New Technologies-Research Center University of West Bohemia\, Plzen\, Czech Republic \n3Fritz Haber Institute of the Max Planck Society\, Faradayweg 4-6\, 14195 Berlin\, Germany \n4Institute of Physics\, École Polytechnique Fédérale de Lausanne\, 1015 Lausanne\, Switzerland \n5Photon Science Division\, Paul Scherrer Institut\, 5232 Villigen PSI\, Switzerland \n6Institut für Halbleiter-und Festkörperphysik\, Johannes Kepler Universität\, A-4040 Linz\, Austria \nα-GeTe(111) is a bulk ferroelectric Rashba semiconductor which exhibits the largest known Rashba-type spin splitting of so-far known materials\, one of the most promising mechanism to reversibly manipulate spin polarization. Its electronic structure in the occupied states has been intensively studied by Angle Resolved Photoemission Spectroscopy (ARPES) and Spin ARPES (SARPES) [1]\, the key technique to understand the spin texture of materials. Using operando SARPES\, it has been demonstrated that it is possible to reversibly manipulate spin polarization by an external electric field in α-GeTe(111) [2] ; a promising behavior for spintronics applications. A stimulating direction of research is to investigate whether it is possible to coherently modify the ferroelectric properties of GeTe upon photoexcitation. \nUsing a 800 nm photoexcitation\, we drive α-GeTe(111) out-of-equilibrium and probe its transient low-energy electronic structure with time-resolved ARPES. We reveal that the Rashba splitting of its bulk states is enhanced after 200 fs. By comparison with density functional theory calculations\, we show that this change of the electronic structure is driven by a shift of the Ge atomic layer towards the Te atomic layer\, meaning an increase of the ferroelectric distortion. A coherent phonon oscillation linked to this ferroelectric distortion is also observed\, with a frequency consistent with the amplitude mode of the related polar mode. \nWe identify a surface photovoltage effect as the mechanism responsible for this transient enhancement of the ferroelectricity at the surface of GeTe and link it to a delayed displacive excitation of the coherent phonon of the ferroelectric distortion. \n\nJ. Krempaský\, S. Muff\, F. Bisti\, M. Fanciulli\, H. Volfová\, A.P. Weber\, N. Pilet\, P. Warnicke\, H. Ebert\, J. Braun\, F. Bertran\, V.V. Volobuev\, J. Minár\, G. Springholz\, J.H. Dil\, and V.N. Strocov\, Nat. Commun. 7\, 13071 (2016).\nJ. Krempaský\, S. Muff\, J. Minár\, N. Pilet\, M. Fanciulli\, A.P. Weber\, E.B. Guedes\, M. Caputo\, E. Müller\, V.V. Volobuev\, M. Gmitra\, C.A.F. Vaz\, V. Scagnoli\, G. Springholz\, and J.H. Dil\, Phys. Rev. X 8\, 021067 (2018).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/claude-monney-transient-enhancement-of-the-ferroelectricity-in-the-rashba-semiconductor-%ce%b1-gete/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T120000 DTEND;TZID=Europe/Ljubljana:20211214T163000 DTSTAMP:20260809T181333 CREATED:20211201T212928Z LAST-MODIFIED:20211201T212928Z UID:1887-1639483200-1639499400@nqw.ijs.si SUMMARY:Lunch DESCRIPTION: URL:https://nqw.ijs.si/event/lunch-2/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T162400 DTEND;TZID=Europe/Ljubljana:20211214T180900 DTSTAMP:20260809T181333 CREATED:20211207T114440Z LAST-MODIFIED:20211207T120325Z UID:2158-1639499040-1639505340@nqw.ijs.si SUMMARY:Chair: Marcin Mierzejewski DESCRIPTION: URL:https://nqw.ijs.si/event/chair-marcin-mierzejewski/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T163000 DTEND;TZID=Europe/Ljubljana:20211214T165500 DTSTAMP:20260809T181333 CREATED:20211201T213346Z LAST-MODIFIED:20211215T151224Z UID:1902-1639499400-1639500900@nqw.ijs.si SUMMARY:Denis Golež: Characterizing microscopic interactions via photo-induced lifetime changes DESCRIPTION:Denis Golež \n1Jožef Stefan Institute\, 1000 Ljubljana\, Slovenia \n2Faculty for mathematics and physics\, University of Ljubljana\, 1000\, Ljubljana\, Slovenia \n*E-mail: (Denis.golez@ijs.si) \nCharge excitations across electronic band gaps are a key ingredient for transport in optoelectronics and light-harvesting applications. In contrast to conventional semiconductors\, studies of above-band-gap photo-excitations in correlated materials are still in their infancy. The new idea presented in this talk is that lifetime changes after a photo-excitation in correlated systems carry essential information about the competition between active degrees of freedom. We will exemplify the concept by a comparative analysis between theoretical many-body simulations and time-resolved ARPES on the excitonic insulator candidate Ta2NiSe5\, where the interplay between electronic and lattice degrees of freedom is a matter of hot debate. We will employ photo-induced changes in the lifetime to quantify the competition between electronic and lattice interactions [1]. In particular\, the distinction between electron-driven versus lattice-driven situation is apparent as in the former\, the photoinduced lifetime changes are substantial\, while in the latter\, they are strongly suppressed. The quantitative comparison between experiment and theory demonstrates the pivotal (but not necessarily sole) contribution of electron-electron interactions to stabilizing the electronic gap in the material. \n\nDG\, Sydney Dufresne\, et al.\, to be published.\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/denis-golez-characterizing-microscopic-interactions-via-photo-induced-lifetime-changes/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T165500 DTEND;TZID=Europe/Ljubljana:20211214T172000 DTSTAMP:20260809T181333 CREATED:20211201T213823Z LAST-MODIFIED:20211215T151243Z UID:1933-1639500900-1639502400@nqw.ijs.si SUMMARY:Zlatko Papic: Dynamics of quantum geometry in the fractional quantum Hall effect DESCRIPTION:A. Kirmani\,1 K. Bull\,2 C.-Y. Hou\,3 Z. Papic\,2 A. Rahmani\,1 P. Ghaemi4 \n1Department of Physics and Astronomy\, Western Washington University\, Bellingham\, Washington 98225\, \n2School of Physics and Astronomy\, University of Leeds\, Leeds LS2 9JT\, United Kingdom \n3Schlumberger-Doll Research\, Cambridge\, MA 02139\, USA \n4Physics Department\, City College of the City University of New York\, New York\, NY 10031\, USA \nIntermediate-scale quantum technologies provide unprecedented opportunities for scientific discoveries while posing the challenge of identifying important problems that can take advantage of them through algorithmic innovations. A major open problem in quantum many-body physics is the table-top generation and detection of emergent excitations analogous to gravitons — the elusive mediators of gravitational force in a quantum theory of gravity. In solid state materials\, fractional quantum Hall phases are one of the leading platforms for realizing graviton-like excitations\, however their direct observation remains an experimental challenge. Here\, we generate these excitations on the IBM quantum processor. We first identify an effective one-dimensional model that captures the geometric properties and graviton dynamics of fractional quantum Hall states. We then develop an efficient\, optimal-control-based variational quantum algorithm to simulate geometric quench and the subsequent graviton dynamics\, which we successfully implement on the IBM quantum computer. Our results [1] open a new avenue for studying the emergence of gravitons in a new class of tractable models that lend themselves to direct implementations on the existing quantum hardware. \n\nA. Kirmani et al.\, arXiv:2107.10267\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/zlatko-papic-dynamics-of-quantum-geometry-in-the-fractional-quantum-hall-effect/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T172000 DTEND;TZID=Europe/Ljubljana:20211214T174500 DTSTAMP:20260809T181333 CREATED:20211201T213547Z LAST-MODIFIED:20211215T151302Z UID:1907-1639502400-1639503900@nqw.ijs.si SUMMARY:Jaka Vodeb: Quantum Domain Melting of a Wigner Crystal in a Quantum Annealer DESCRIPTION:J. Vodeb\,1\,2 M. Diego\,1 Y. Vaskivskyi\,1 L. Logaric\,1 Y. Gerasimenko\,1 V. Kabanov\,1 B. Lipovsek\,3 M. Topic\,3 D. Mihailovic1\,2\,4 \n1Department of Complex Matter\, Jozef Stefan Institute\, Jamova 39\, SI-1000 Ljubljana\, Slovenia \n2Department of Physics\, Faculty for Mathematics and Physics\, Jadranska 19\, University of Ljubljana\, SI-1000 Ljubljana\, Slovenia \n3Faculty for Electrical Engineering\, University of Ljubljana\, 1000 Ljubljana\, Slovenia \n4CENN Nanocenter\, Jamova 39\, 1000 Ljubljana\, Slovenia \nThe ordering of systems emerging through non-equilibrium symmetry breaking transitions is inevitably accompanied by domain formation. The underlying microscopic physics that defines the system‘s energy landscape for tunneling between domain configurations is of interest in many different areas of physics\, ranging from cosmology to solid state quantum matter [1-8]. Domains may reconfigure by thermally-driven microscopic processes [9\,10]\, or – in quantum systems – by macroscopic quantum tunneling. Here\, we report quantum domain melting dynamics in two embodiments: an electronic crystal 1T-TaS2\, and its matching simulation on a quantum computer [11]. We use scanning tunneling microscopy to measure the time-evolution of electronic domain reconfiguration dynamics in real time\, and compare this with the time evolution of domains in an ensemble of entangled correlated electrons in simulated quantum domain melting. The domain reconfiguration is found to proceed by tunneling between minima in a self-configuring energy landscape. A quantum charged lattice gas model is set up in a quantum annealer\, that closely matches the experiment. Both are seen to exhibit characteristic ragged time evolution and temperature-dependence observed macroscopically averaged over the ensemble. Understanding the quantum processes involved in electronic domain melting opens the way to understanging non-equilibrium interacting many-body quantum systems at the microscopic level. \n\nM. S. Turner and F. Wilczek\, “Is our vacuum metastable?” (1982)\nB. M. Roberts et al.\, Nature Communications 8\, 1 (2017)\nS. Coleman\, Physical Review D 15\, 2929 (1977)\nS. Kustov et al.\, Physical Review Letters 124\, 016801 (2020)\nL. Thomas et al.\, Nature 383\, 145–147 (1996)\nE. M. Chudnovsky and J. Tejada\, Cambridge University Press (1998)\nA. Kandala et al.\, Nature 549\, 242 (2017)\nD. D. Awschalom et al.\, Physical Review Letters 68\, 3092 (1992)\nL. P. Pitaevskii and E. M. Lifshitz\, Physical Kinetics: Volume 10 (2012)\nA. Baldan\, Journal of Materials Science 37\, 2171 (2002)\nA. D. King et al.\, Nature Communications 12\, 1 (2021)\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/jaka-vodeb-quantum-domain-melting-of-a-wigner-crystal-in-a-quantum-annealer/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T174500 DTEND;TZID=Europe/Ljubljana:20211214T181000 DTSTAMP:20260809T181333 CREATED:20211201T213547Z LAST-MODIFIED:20211215T151341Z UID:1908-1639503900-1639505400@nqw.ijs.si SUMMARY:Tomaz Mertelj: Ultrafast dynamics of Mott-state quench and formation in strongly correlated BEDT-TTF molecular conductors observed by three-pulse pump probe spectroscopy DESCRIPTION:S. Tsuchiya\,1\,2 H. Taniguchi\,1 J. Yamada\,3 Y. Toda\,2 D. Mihailovic\,1\,4 T. Mertelj1\,4 \n1Complex Matter Department\, Jozef Stefan Institute\, Jamova 39\, Ljubljana\, SI-1000\, Slovenia \n2Department of Applied Physics\, Hokkaido University\, Sapporo\, Hokkaido 060-8628\, Japan \n3Graduate School of Material Science\, University of Hyogo\, Hyogo 678-1205\, Japan \n4Center of Excellence on Nanoscience and Nanotechnology Nanocenter (CENN Nanocenter)\, Jamova 39\, 1000 Ljubljana\, Slovenia \nWe investigate the quench and real-time formation of the Mott state and photoexcited carrier relaxation dynamics in the Mott insulator κ-(BEDT-TTF)2Cu[N(CN)2]Cl (κ-Cl) and the superconductor κ-(BEDT-TTF)2Cu[N(CN)2]Br (κ-Br) using three-pulse femtosecond optical spectroscopy. In both salts\, we find that transient reflectivity amplitude recovers on 2 ps timescale after a strong near-infrared pulse quench. The transient reflectivity relaxation time is nearly constant throughout indicating that the energy gap for charge excitations is filled rather than closed\, by photoinduced carriers of only 0.5% per dimer site. The Mott state is re-formed on a few-picosecond timescale with the disappearance of the in-gap photo-doping induced states near the Fermi energy. In κ-Br\, a similar behavior to that in κ-Cl is observed and attributed to the disorder induced phase-separated Mott insulating regions [2]. \n\nS. Tsuchiya et al.\, Phys. Rev. B 104\, 115152 (2021).\nY. Toda\, et al.\, Phys. Rev. Lett. 107\, 227002 (2011).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/tomaz-mertelj-ultrafast-dynamics-of-mott-state-quench-and-formation-in-strongly-correlated-bedt-ttf-molecular-conductors-observed-by-three-pulse-pump-probe-spectroscopy/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T181000 DTEND;TZID=Europe/Ljubljana:20211214T200000 DTSTAMP:20260809T181333 CREATED:20211201T212928Z LAST-MODIFIED:20211201T212928Z UID:1888-1639505400-1639512000@nqw.ijs.si SUMMARY:Dinner DESCRIPTION: URL:https://nqw.ijs.si/event/dinner-3/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T195900 DTEND;TZID=Europe/Ljubljana:20211214T210000 DTSTAMP:20260809T181333 CREATED:20211207T103746Z LAST-MODIFIED:20211210T134734Z UID:2146-1639511940-1639515600@nqw.ijs.si SUMMARY:Chair: Jaka Vodeb DESCRIPTION: URL:https://nqw.ijs.si/event/chair-jaka-vodeb/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T200000 DTEND;TZID=Europe/Ljubljana:20211214T202500 DTSTAMP:20260809T181333 CREATED:20211201T213823Z LAST-MODIFIED:20211215T151400Z UID:1934-1639512000-1639513500@nqw.ijs.si SUMMARY:Chong-Yu Ruan: Nonthermal control of excited quantum materials via laser interaction quench DESCRIPTION:Chong-Yu Ruan1 \n1Department of Physics and Astronomy\, Michigan State University\, East Lansing\, MI 48824\, USA \nQuantum material systems upon applying ultrashort laser pulses provide a rich platform to access excited material phases and their transformations that are not entirely like their equilibrium counterparts. The addressability and potential controls of metastable or long- trapped out-of-equilibrium phases have motivated interests both for the purposes of understanding the nonequilibrium physics and advancing the quantum technologies. \nThus far\, the dynamical spectroscopic probes eminently focus on microscopic electronic and phonon responses. For characterizing the long-range dynamics\, such as order parameter fields and fluctuation effects\, the ultrafast scattering probes offer direct sensitivity. Bridging the connections between the microscopic dynamics and macroscopic responses is central toward establishing the nonequilibrium physics behind the light-induced phases. \nLearning from the quantum gases microscope experiments and the nonequilibrium sciences on atomic and molecular systems\, we present a path to understand the nonequilibrium many-body dynamics using excited quantum material phases as a platform. We first highlight the synergies based on phenomenology to identify common open questions and potentially different manifestations in hard condensed matter systems. To this end\, we give the basic theoretical framework on describing the non-equilibrium scattering problems and describe how such framework relates to the out-of-equilibrium phenomena. \nOn the experimental realizations\, the focus will be placed on the short-time behaviors mediated by interaction quench. We give effective models outlining the emergences of nonthermal critical points\, and hidden phases setting the initial condition for the long-time relaxation dynamics as the system re-establish the thermal states[1]. In particular\, the inhomogeneity embedded in the system formation and their impacts on the dynamical evolutions into especially the long-time trapped states stemming from interaction quench are of particular interests. \nFollowing the phenomenology\, rich scenarios as those involve competitive broken-symmetry orders\, vestigial orders\, and the intertwined ground states could be identified\, leading to intriguing nonequilibrium phenomena from vacuum- suspended rare-earth tritellurides[2]\, tantalum disulfides[3] thin films\, and vanadium dioxide nanocrystalline materials[4] upon light excitations re-examined in recent experiments. \n\nX. Sun\, S. Sun\, C.-Y. Ruan\, Comptes Rendus. Physique\, Online first (2021)\, 1-59 (2021).\nF. Zhou et al. Nature Communications 12\, 566 (2021).\nT.-R.T. Han et al. Science Advances 1\, e1400173 (2015).\nZ. Tao et al. Scientific Reports 6\, 38514 (2016).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/chong-yu-ruan-nonthermal-control-of-excited-quantum-materials-via-laser-interaction-quench/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T202500 DTEND;TZID=Europe/Ljubljana:20211214T204000 DTSTAMP:20260809T181333 CREATED:20211201T213903Z LAST-MODIFIED:20211215T151429Z UID:1943-1639513500-1639514400@nqw.ijs.si SUMMARY:Rok Venturini: Ultra-efficient resistance switching between charge ordered phases in 1T-TaS2 with a single picosecond electrical pulse DESCRIPTION:Rok Venturini\,1\,2 Anže Mraz\,1\,3 Igor Vaskivskyi\,1 Yevhenii Vaskivskyi\,1\,2 Damjan Svetin\,1\,4 Tomaž Mertelj\,1 Jing Cheng\,5 Genyu Chen\,5 Priyanthi Amarasinghe\,6 Syed B. Qadri\,7 Sudhir B. Trivedi\,6 Roman Sobolewski\,5\,8 and Dragan Mihailovic1\,4 \n1Jožef Stefan Institute\, Jamova 39\, Ljubljana\, SI-1000\, Slovenia\, \n2Department of Physics\, Faculty of Mathematics and Physics\, University of Ljubljana\, Jadranska 19\, Ljubljana\, SI-1000\, Slovenia \n3Faculty for Electrical Engineering\, University of Ljubljana\, Tržaška 25\, SI-1000 Ljubljana\, Slovenia \n4CENN Nanocenter\, Jamova 39\, SI-1000 Ljubljana\, SI-1000\, Slovenia \n5Materials Science Program and Laboratory for Laser Energetics\, University of Rochester\, New York 14627\, USA \n6Brimrose Technology Corporation\, Sparks\, MD 21152\, USA \n7U.S. Naval Research Laboratory\, Washington D.C.\, USA \n8Department of Electrical and Computer Engineering and Department of Physics and Astronomy\, University of Rochester\, New York 14627\, USA \nResistance switching between charge ordered phases of the 1T-TaS₂ has shown to be potentially useful for the development of high-speed\, energy efficient non-volatile memory devices1\,2. While ultrafast switching was previously reported with optical pulses3\, determination of the intrinsic speed limits of actual devices that are triggered by electrical pulses is technically challenging and hitherto still largely unexplored. \nUsing an optoelectronic “laboratory-on-a-chip” especially designed for measurements of ultrafast memory switching\, we are able to accurately measure the electrical switching parameters with sub-100 fs temporal resolution. A photo-switch is used for ultrashort electrical pulse generation\, while its propagation along a coplanar transmission line\, and across the memory device\, is detected using electro-optical sampling using a purpose-grown highly-resistive electro-optic (Cd\,Mn)Te crystal substrate. \nWe observe non-volatile resistance switching with single 1.9 ps electrical pulses\, with a switching energy of 0.47 atto-Joules. This represents a significant advance over existing non-volatile memory device concepts in terms of both parameters. The ground-breaking result suggest that electrical charge manipulation in 1T-TaS2 could become a new technological platform for cryogenic\, ultrahigh-speed\, energy efficient memory devices. \n\nVaskivskyi\, I. et al. Nat. Commun. 7\, 11442 (2016).\nMraz\, A. et al. arXiv 2103.04622\, (2021).\nRavnik\, J.\, Vaskivskyi\, I.\, Mertelj\, T. & Mihailovic\, D. Phys. Rev. B 97\, 075304 (2018).\n\n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/rok-venturini-ultra-efficient-resistance-switching-between-charge-ordered-phases-in-1t-tas2-with-a-single-picosecond-electrical-pulse/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T204000 DTEND;TZID=Europe/Ljubljana:20211214T205500 DTSTAMP:20260809T181333 CREATED:20211201T213919Z LAST-MODIFIED:20211215T151503Z UID:1948-1639514400-1639515300@nqw.ijs.si SUMMARY:Matteo Zendra: Many-body tunnelling in a symmetric double-well potential DESCRIPTION:M. Zendra\,1\,2 S. Gurvitz\,3 G. L. Celardo\,4 F. Borgonovi1\,2 \n1Department of Mathematics and Physics and Interdisciplinary Laboratories for Advanced \nMaterials Physics\, Università Cattolica del Sacro Cuore\, Brescia\, Italy \n2National Institute for Nuclear Physics\, Sezione di Milano\, Milano\, Italy \n3Department of Particle Physics\, Weizmann Institute of Science\, Rehovot\, Israel \n4Physics and Astronomy department\, Università degli studi di Firenze\, Firenze\, Italy \nTunnelling is one of the most fascinating phenomena in quantum physics\, whose implications on the dynamics of many-body systems are still unclear. Recently\, it has been argued that the presence of inter-particle interactions may lead to cooperative effects\, such as the modification of the single-particle tunnelling between wells or the simultaneous tunnelling of a few particles as a single object through a potential barrier. Under certain conditions\, these non-standard Hubbard terms are considerably more important than previously assumed\, due to correct account of the Wannier functions\, which tails were disregarded in many estimations. In this talk\, we will examine some preliminary results about possible cooperative effects shown by two particles in a double-well potential\, under the effect of different types of interaction. Our results show that\, under certain conditions\, the non-standard density-induced tunnelling amplitude may suppress the single-particle tunnelling even for repulsive two-particle interactions. This would correspond to a bound state localized in one well\, which cannot decay but only propagate between the wells due to the non-standard pair-tunnelling mechanism. \n\n\nWatch the lecture:\n\n \n Protected Area\n This content is password-protected. Please verify with a password to unlock the content. \n \n \n Enter your password\n \n \n Unlock URL:https://nqw.ijs.si/event/matteo-zendra-many-body-tunnelling-in-a-symmetric-double-well-potential/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211214T210000 DTEND;TZID=Europe/Ljubljana:20211214T220000 DTSTAMP:20260809T181333 CREATED:20211201T212928Z LAST-MODIFIED:20211201T212928Z UID:1889-1639515600-1639519200@nqw.ijs.si SUMMARY:Social event DESCRIPTION: URL:https://nqw.ijs.si/event/social-event/ CATEGORIES:NQW 2021 END:VEVENT END:VCALENDAR