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:20211216T085900 DTEND;TZID=Europe/Ljubljana:20211216T101400 DTSTAMP:20260809T140944 CREATED:20211207T121234Z LAST-MODIFIED:20211207T121234Z UID:2183-1639645140-1639649640@nqw.ijs.si SUMMARY:Chair: Tomaž Prosen DESCRIPTION: URL:https://nqw.ijs.si/event/chair-tomaz-prosen/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T090000 DTEND;TZID=Europe/Ljubljana:20211216T092500 DTSTAMP:20260809T140944 CREATED:20211201T213734Z LAST-MODIFIED:20211217T094751Z UID:1922-1639645200-1639646700@nqw.ijs.si SUMMARY:Gabriel Aeppli: TBA 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/gabriel-aeppli-tba/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T092500 DTEND;TZID=Europe/Ljubljana:20211216T095000 DTSTAMP:20260809T140944 CREATED:20211201T213603Z LAST-MODIFIED:20211217T110432Z UID:1915-1639646700-1639648200@nqw.ijs.si SUMMARY:Jan Suntajs: Spectral properties of the three-dimensional Anderson model DESCRIPTION:J. Šuntajs\,1 T. Prosen\,1 L. Vidmar1\,2 \n1Department of Theoretical Physics\, J. Stefan Institute\, SI-1000 Ljubljana\, Slovenia \n2Department of Physics\, Faculty of Mathematics and Physics\, University of Ljubljana\, SI-1000 Ljubljana\, Slovenia \nThe three-dimensional Anderson model represents a paradigmatic model to understand the Anderson localization transition. Using modern numerical approaches\, we investigate the model’s spectral properties\, focusing particularly on the quantitative comparison between the level sensitivity statistics and the level statistics. While the former probes the susceptibility of the Hamiltonian eigenlevels towards the introduction of the magnetic flux to the system\, the latter deals with the unperturbed energy levels. We define two versions of the dimensionless conductance\, the first corresponding to the width of the level curvature distribution relative to the mean level spacing\, and the other corresponding to the ratio of Heisenberg and Thouless times obtained from the spectral form factor. We show that both conductances display remarkably similar behaviour around the localization transition\, in particular\, they predict a nearly identical critical point consistent with other well-established measures of the transition. \nMotivated by the pioneering work of Edwards and Thouless [J. Phys. C. 5\, 807 (1972)]\, we then calculate the characteristic energy\, defined as the mean change of the eigenlevels upon switching the hopping along one of the lattice edges from periodic to antiperiodic boundary conditions. Making use of the modern hardware to perform a systematic analysis\, we obtain results for system sizes much greater than the ones available to the authors of the original study. By accurately pinpointing the location of the critical point\, we establish the latter method as a reliable tool for detecting the localization transition in noninteracting systems. In the context of the spectral form factor\, we show that at the critical point it enters a broad time-independent regime\, in which its value is consistent with the level compressibility obtained from the level variance. Finally\, we test the scaling solution of the average level spacing ratio in the crossover regime using the cost function minimization approach introduced recently in [Phys. Rev. B.\, 102\, 064207 (2020)]. The latter approach seeks for the optimal scaling solution in the vicinity of the crossing point\, while at the same time allowing for the drift of the crossing point due to finite-size corrections. We find that the extracted transition point and the scalling coefficient accurately agree with those obtained from the literature. \n\nJ. Šuntajs et. al. Annals of Physics\, 168469 (2021)\nJ. Šuntajs et. al. Phys. Rev. B 102\, 064207 (2020)\nJ. Edwards\, E. Thouless\, J. Phys. C. 5\, 807 (1972)\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/jan-suntajs-spectral-properties-of-the-three-dimensional-anderson-model/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T095000 DTEND;TZID=Europe/Ljubljana:20211216T101500 DTSTAMP:20260809T140944 CREATED:20211201T213848Z LAST-MODIFIED:20211217T110458Z UID:1939-1639648200-1639649700@nqw.ijs.si SUMMARY:Feliks Fritzsch: Boundary Chaos DESCRIPTION:F. Fritzsch\,1 T. Prosen1 \n1Faculty of Mathematics and Physics\, University of Ljubljana \, Jadranska ulica 19\, SI-1000 Ljubljana\, Slovenia \nSpatiotemporal correlation functions provide the key diagnostic tool for studying spatially extended complex quantum many-body systems. In ergodic systems scrambling causes initially local observables to spread uniformly over the whole available Hilbert space and causes exponential suppression of correlation functions with the spatial size of the system. In this talk\, we present a perturbed free quantum circuit model\, in which ergodicity is induced by a unitary impurity placed on the system‘s boundary and that allows for demonstrating the underlying mechanism governing the asymptotic scaling of correlations with system size. \nThis is achieved by mapping dynamical correlation functions of local operators in a system of linear size L at time t to a partition function with complex weights defined on a two-dimensional lattice of smaller size t/L × L with a helix topology. We evaluate this partition function in terms of suitable transfer matrices. As this drastically reduces the complexity of the computation of correlation functions\, we are able to treat system sizes far beyond what is accessible by exact diagonalization. By studying the spectra of transfer matrices numerically and combining our findings with analytical arguments we determine the asymptotic scaling of correlation functions with system size. \nFor impurities that remain unitary under partial transpose\, we demonstrate that correlation functions at times proportional to system size L are generically exponentially suppressed with L. In contrast\, for generic unitary impurities correlations show persistent revivals with a period given by the system size. \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/feliks-fritzsch-boundary-chaos/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T101500 DTEND;TZID=Europe/Ljubljana:20211216T104500 DTSTAMP:20260809T140944 CREATED:20211201T213129Z LAST-MODIFIED:20211204T085855Z UID:1895-1639649700-1639651500@nqw.ijs.si SUMMARY:Coffee break DESCRIPTION: URL:https://nqw.ijs.si/event/coffee-break-3/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T104400 DTEND;TZID=Europe/Ljubljana:20211216T115900 DTSTAMP:20260809T140944 CREATED:20211207T121340Z LAST-MODIFIED:20211207T121341Z UID:2186-1639651440-1639655940@nqw.ijs.si SUMMARY:Chair: Miroslav Hopjan DESCRIPTION: URL:https://nqw.ijs.si/event/chair-miroslav-hopjan/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T104500 DTEND;TZID=Europe/Ljubljana:20211216T110000 DTSTAMP:20260809T140944 CREATED:20211201T213903Z LAST-MODIFIED:20211217T110522Z UID:1944-1639651500-1639652400@nqw.ijs.si SUMMARY:Valentina Gosetti: Photoinduced modulation of the excitonic resonance via coupling with coherent phonons in a layered semiconductor DESCRIPTION:S. Mor\,1\,2 V. Gosetti\,1\,2\,9 A. Molina-Sanchéz\,3 D. Sangalli\,4\,6 S. Achilli\,5\,6 V. F. Agekyan\,7 P. Franceschini\,1\,2\,8 C. Giannetti\,1\,2 L. Sangaletti\,1\,2 S. Pagliara1\,2 \n1Department of Mathematics and Physics\, Università Cattolica\, I-25121 Brescia\, Italy2Interdisciplinary Laboratories for Advanced Materials Physics (I-LAMP)\,Università Cattolica\, I-25121 Brescia\, Italy3Institute of Materials Science (ICMUV)\, University of Valencia\, Catedrático Beltrán 2\, E-46980 Valencia\, Spain4Istituto di Struttura della Materia-CNR (ISM-CNR)\, Division of Ultrafast Processesin Materials (FLASHit)\, Area della Ricerca di Roma 1\, Monterotondo Scalo\, Italy5Dipartimento di Fisica\, Università degli Studi di Milano\, via Celoria 6\, 20133 Milano\, Italy6European Theoretical Spectroscopy Facility\, ETSF7St. Petersburg State University\, St. Petersburg\, 199034\, Russia8Department of Physics and Astronomy\, KU Leuven\, Celestijnenlaan 200D\,3001 Leuven\, Belgium9Department of Materials Engineering\, KU Leuven\, Kasteelpark Arenberg 44\,3001 Leuven\, Belgium \nThe discovery of graphene in 2004 has opened a new field of research about two-dimensional (2D) materials. Nowadays\, by virtue of the tunability of their electronic and structural properties\, 2D materials are applied in a great variety of areas like\, for example\, sensors\, energy storage\, and photonic devices. Among the emerging 2D materials\, we have focused our attention on the van-der-Waals-layered semiconductor bismuth tri-iodide (BiI3). \nFirst of all\, BiI3 exhibits a clear and isolated absorption resonance in the visible range\, detectable also at room temperature. Besides this\, the lattice vibration is dominated by an out-of-plane Ag mode. The co-presence of these two degrees of freedom makes BiI3 an ideal candidate to be used in the investigation of exciton-phonon coupling. \nHowever\, how exciton-phonon coupling manifests in the time and energy domains is still an open debate between experiment and theory. Through time-resolved broadband reflectivity\, we investigate the ultrafast optical response of BiI3 single crystal. Our measurements reveal a multi-step electron relaxation dynamic with time constants that range from a few hundreds of femtoseconds up to tens of nanoseconds\, superimposed by a periodic intensity modulation ascribed to the generation of coherent optical phonons. Here\, we will focus only on the coherent optical response of BiI3. \nOur joint theoretical and experimental effort allows uncovering the relationship between the photoinduced periodic excitonic energy modulation and the generation of coherent optical phonons. Moreover\, employing ab-initio DFT calculation coupled with a transient analysis of the experimental results\, we were able to extrapolate the photoinduced atomic displacement in the real space from the excitonic energy modulation. \nIn conclusion\, with our work([1])\, we set the spectral fingerprints for the optical detection of exciton-phonon coupling in layered semiconductors. Moreover\, our findings represent a step forward on the road to coherent manipulation of the excitonic properties on ultrafast timescales. \n\nS. Mor et al. Phys. Rev. Research\, accepted\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/valentina-gosetti-photoinduced-modulation-of-the-excitonic-resonance-via-coupling-with-coherent-phonons-in-a-layered-semiconductor/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T110000 DTEND;TZID=Europe/Ljubljana:20211216T111500 DTSTAMP:20260809T140944 CREATED:20211201T213919Z LAST-MODIFIED:20211217T110546Z UID:1947-1639652400-1639653300@nqw.ijs.si SUMMARY:Banhi Chatterjee: Electronic and lattice properties of Ta2NiSe5- an excitonic insulator candidate 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/banhi-chatterjee-electronic-and-lattice-properties-of-ta2nise5-an-excitonic-insulator-candidate/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T111500 DTEND;TZID=Europe/Ljubljana:20211216T113000 DTSTAMP:20260809T140944 CREATED:20211201T213919Z LAST-MODIFIED:20211217T110710Z UID:1949-1639653300-1639654200@nqw.ijs.si SUMMARY:Luka Pavešič: Subgap states in superconducting islands DESCRIPTION:L. Pavešič\,1\,2 R. Žitko1\,2 \n1Jožef Stefan Institute\, Jamova 39\, SI-1000 Ljubljana\, Slovenia \n2Faculty of Mathematics and Physics\, University of Ljubljana\, Jadranska 19\, SI-1000 Ljubljana\, Slovenia \nThe local magnetic moment of an interacting quantum dot can be screened by a Bogoliubov quasiparticle from a nearby superconductor. This gives rise to a long lived discrete spin singlet state inside the superconducting gap\, known as the Yu-Shiba-Rusinov (YSR) state. \nWe study the nature of the subgap states in a quantum dot coupled to one or two superconducting islands. These are described by a number conserving Richardson model of superconductivity\, which allows us to account for the charging energy of the superconducting islands. For charging energy comparable to the superconducting gap\, the subgap states are stabilized by a combination of Kondo exchange screening and charge redistribution driven by the Coulomb interaction. The model predictions match experimental results very well. \nThere are two singlet subgap states in the case of a quantum dot embedded between two superconducting channels\, corresponding to the formation of a YSR singlet in each channel. The system can be tuned to a regime where the subgap states can be put into a superposition and coherently manipulated by electronic pulses. Such a qubit could be implemented using known technology. \nIn the doublet spin sector we investigate the overscreened state. Overscreening in normal state systems leads to a fixed point in the renormalization flow with non Fermi liquid properties\, while for superconducting islands it emerges as a doublet subgap state with curious spin properties. \n\nL. Pavešič et al.\, arXiv:2101.10168\nJ. C. Estrada Saldaña et al.\, arXiv:2101.10794\nL. Pavešič\, R. Žitko\, arXiv:2110.13881\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/luka-pavesic-subgap-states-in-superconducting-islands/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211216T113000 DTEND;TZID=Europe/Ljubljana:20211216T114000 DTSTAMP:20260809T140944 CREATED:20211201T213129Z LAST-MODIFIED:20211217T111629Z UID:1896-1639654200-1639654800@nqw.ijs.si SUMMARY:Closing 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/closing/ CATEGORIES:NQW 2021 END:VEVENT END:VCALENDAR