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:20211213T085900 DTEND;TZID=Europe/Ljubljana:20211213T104500 DTSTAMP:20260810T010855 CREATED:20211207T074932Z LAST-MODIFIED:20211207T120127Z UID:2134-1639385940-1639392300@nqw.ijs.si SUMMARY:Chair: Dragan Mihailović DESCRIPTION: URL:https://nqw.ijs.si/event/chair-dragan-mihailovic/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T090000 DTEND;TZID=Europe/Ljubljana:20211213T092500 DTSTAMP:20260810T010855 CREATED:20211201T213734Z LAST-MODIFIED:20211214T081402Z UID:1923-1639386000-1639387500@nqw.ijs.si SUMMARY:Uwe Bovensiepen: Microscopic dynamics of propagating and localized excitations across interfaces analyzed by femtosecond solid state spectroscopy DESCRIPTION:Uwe Bovensiepen \nFaculty of Physics\, University of Duisburg-Essen\, Germany \ne-mail: uwe.bovensiepen@uni-due.de \nAn excited electron propagates in condensed matter with its momentum k at an energy E(k) and experiences elastic and inelastic scattering processes\, which lead to electronic relaxation and energy transfer to microscopic excitations of the lattice and spin systems. Experiments employing femtosecond time-resolved photoelectron spectroscopy exploited so far very successfully the surface sensitivity of the method and probed such scattering processes locally at or near the surface in the time domain [1]. Here\, we report on experimental results which analyze the non-local dynamics of excited electrons in two-photon photoemission (2PPE) and demonstrate sensitivity to buried media [2]. In these experiments one photon excites in Au/Fe/MgO(001) heterostructures electrons in Fe. Electron propagation through the layer stack to the Au surface is detected in 2PPE in back side pump – front side probe experiments in a time-of-flight like scheme. We observe pronounced differences between front and back side pumping of the heterostructure which are attributed to electron transport contributions through the layer stack. Furthermore\, competition of e-e with e-ph scattering will be discussed in [Fe/MgO]n heterostructures. Pump-probe experiments of element specific spectroscopy in combination with electron diffraction provide here unprecedented insights regarding the mechanism of energy transfer across interfaces and emphasize the importance of coupling hot electrons to non-thermalized interface phonons [3]. Extension of these experimental tools to address effects of strong electron correlation [4] and spin-dependent dynamics across interfaces [5] will be discussed. \nThis work was funded by the Deutsche Forschungsgemeinschaft through the Collaborative Research Center CRC 1242. \n\nU. Bovensiepen\, H. Petek\, M. Wolf\, Dynamics at Solid State Surface and Interfaces\, Vol. 1\, Wiley-VCH\, 2010.\nY. Beyazit J. Beckord\, P. Zhou\, J. Meyburg\, F. Kühne\, D. Diesing\, M. Ligges\, U. Bovensiepen\, Phys. Rev. Lett. 125\, 076803 (2020).\nN. Rothenbach\, M. E. Gruner\, K. Ollefs\, C. Schmitz-Antoniak\, S. Salamon\, P. Zhou\, R. Li\, M. Mo\, S. Park\, X. Shen\, S. Weathersby\, J. Yang\, X. J. Wang\, R. Pentcheva\, H. Wende\, U. Bovensiepen\, K. Sokolowski-Tinten\, A. Eschenlohr\, Phys. Rev. B 100\, 174301 (2019).\nN. Rothenbach\, M. E. Gruner\, K. Ollefs\, C. Schmitz-Antoniak\, S. Salamon\, P. Zhou\, R. Li\, M. Mo\, S. Park\, X. Shen\, S. Weathersby\, J. Yang\, X. J. Wang\, O. Sipr\, H. Ebert\, K. Sokolowski-Tinten\, R. Pentcheva\, U. Bovensiepen\, A. Eschenlohr\, H. Wende\, Phys. Rev. B 104\, 144302(2021).\nM. Ligges\, I. Avigo\, D. Golez\, H. U. R. Strand\, Y. Beyazit\, K. Hanff\, F. Diekmann\, L. Stojchevska\, M. Kalläne\, K. Rossnagel\, M. Eckstein\, P. Werner\, U. Bovensiepen\, Phys. Rev. Lett. 120\, 166401 (2018).\nJ. Chen\, U. Bovensiepen\, A. Eschenlohr\, T. Müller\, P. Elliott\, E. K. U. Gross\, J. K. Dewhurst\, S. Sharma\, Phys. Rev. Lett. 122\, 067202 (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/uwe-bovensiepen-microscopic-dynamics-of-propagating-and-localized-excitations-across-interfaces-analyzed-by-femtosecond-solid-state-spectroscopy/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T092500 DTEND;TZID=Europe/Ljubljana:20211213T095000 DTSTAMP:20260810T010855 CREATED:20211201T213603Z LAST-MODIFIED:20211214T081912Z UID:1916-1639387500-1639389000@nqw.ijs.si SUMMARY:Julian Maklar: Coherent Control of a Metastable Hidden Phase DESCRIPTION:J. Maklar\,1 S. Dong\,1 J. Sarkar\,1 T. Pincelli\,1 P.S. Kirchmann\,2 J.A. Sobota\,2 S. Yang\,2 R.G. Moore\,2 Z.-X. Shen\,2 S. Beaulieu\,1\,3 M. Wolf\,1 Y.A. Gerasimenko\,4\,5\,6 D. Mihailovic\,4\,5 R. Ernstofer\,1\,7 L. Rettig1 \n1Fritz-Haber-Institut der Max-Planck-Gesellschaft\, Faradayweg 4-6\, Berlin\, Germany \n2Stanford Institute for Materials and Energy Sciences\, SLAC National Accelerator Laboratory\, 2575 Sand Hill Road\, Menlo Park\, California 94025\, USA \n3Université de Bordeaux – CNRS – CEA\, CELIA\, UMR5107\, F33405\, Talence\, France \n4Dept. of Complex Matter\, Jožef Stefan Institute\, Jamova 39\, SI-1000 Ljubljana\, Slovenia \n5Center of Excellence on Nanoscience and Nanotechnology\, Jamova 39\, SI-1000 Ljubljana\, Slovenia \n6Department of Physics\, University of Regensburg\, Regensburg\, Germany \n7Institut für Optik und Atomare Physik\, Technische Universität Berlin\, Straße des 17. Juni 135\, Berlin\, Germany \nControlling material properties by illumination with ultrashort optical pulses is a promising new pathway to extend the functionality of complex solids. Prominent examples of this rapidly growing research field include photostabilization of superconductivity [1] and switching to metastable states not accessible in thermal equilibrium [2]. A metastable state of particular interest is the optically or electrically induced hidden phase of 1T-TaS2\, as it features an order-of-magnitude change in resistivity [3]\, which allows for novel energy-efficient high-speed memory devices [4]. However\, so far a clear understanding of the microscopic processes that govern the dynamic pathways to metastable states is still missing\, limiting controllability due to empirical and unspecific switching protocols. \nHere\, using time- and angle-resolved photoemission spectroscopy (trARPES)\, we investigate the electronic band structure and ultrafast photoinduced phase transition from commensurate charge-density-wave (CDW) ground state to the hidden state in 1T-TaS2. Mapping the band structure of the hidden state reveals suppression of correlation effects and confirms metallization\, suggesting a critical role of interlayer stacking order of the TaS2 sheets in the hidden state. Next\, we track the fluence-dependent electron dynamics upon photoexcitation and find strong evidence that the CDW amplitude mode governs a collective\, ultrafast switching pathway to the hidden state. This is further corroborated by demonstrating coherent control of the switching efficiency into the hidden phase by controlling the CDW amplitude mode using a multi-pump-pulse excitation scheme. We envision that the amplitude-mode governed transition applies to a range of CDW compounds [5]. \n\nM. Budden et al.\, Nat. Phys. 17\, 611-618 (2021)\nV.R. Morrison et al.\, Science 346\, 6208 ( 2014)\nL. Stojchevska et al.\, Science 344\, 6180 (2014)\nA. Mraz et al.\, arXiv preprint 2103.04622 (2021)\nN. Yoshikawa et al.\, Nat. Phys. 17\, 909-914 (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/julian-maklar-coherent-control-of-a-metastable-hidden-phase/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T095000 DTEND;TZID=Europe/Ljubljana:20211213T101500 DTSTAMP:20260810T010855 CREATED:20211201T213734Z LAST-MODIFIED:20211214T082016Z UID:1924-1639389000-1639390500@nqw.ijs.si SUMMARY:Jimin Zhao: Ultraweak electron-phonon coupling strength in cubic boron arsenide unveiled by ultrafast dynamics DESCRIPTION:Jimin Zhao \nInstitute of Physics\, Chinese Academy of Sciences\, Beijing China \nWe report a time-resolved ultrafast quasiparticle dynamics investigation of cubic boron arsenide (c-BAs)\, which is a recently discovered highly thermal conducting material. The excited state ultrafast relaxation channels dictated by the electron-phonon coupling (EPC)\, phonon-phonon scattering\, and radiative electron-hole recombination have been unambiguously identified\, along with their typical interaction times [1]. Significantly\, the EPC strength is obtained from the dynamics\, with a value of  λ = 0.008\, demonstrating an unusually weak coupling between the electrons and phonons. As a comparison\, an ultraweak EPC strength for graphene is also expected. Notably\, during our analysis we have generalized the fluence-dependence method for obtaining the EPC strength to room temperature\, which can be applied to many other types of quantum materials in the future. \nTime permits\, I will also talk about two other recent progresses: (1) We have conceived and constructed an on-site in situ high-pressure ultrafast pump-probe spectroscopy instrument that facilitates ultrafast pump-probe dynamics measurements under high pressure condition [2]. (2) We demonstrate that second harmonic generation (SHG) is a local microscopic process—it does not rely on macroscopic broken inversion symmetry [3]. An AB-type superstructure can generate SHG easily and an ABC-type super-structure is not necessary. Our results introduce a scheme for SHG\, extending the generation and control of SHG in nano-photonics to nearly all the accessible centrosymmetric materials. \n\nZ. Y. Tian\, Y. W. Xiao\, Q. Y. Zhang\, G. A. Gamage\, F. Tian\, S. Yue\, V. G. Hadjiev\, Jiming Bao\, Zhifeng Ren\, Erjun Liang\,† and Jimin Zhao*\, Ultraweak electron-phonon coupling strength in cubic boron arsenide unveiled by ultrafast dynamics\, Submitted (2021).\nY. L. Wu\, X. Yin\, J. Z. L. Hasaien\, Z. Y. Tian\, Yang Ding\, and Jimin Zhao*\, On-site in situ high-pressure ultrafast pump-probe spectroscopy instrument\, Rev. of Sci. Instrum. 92\, 113002 (2021).\nHui Zhao\, Qichang An\, X. Ye\, B. H. Yu\, Q. H. Zhang\, F. Sun\, Q. Y. Zhang\, Fang Yang\, Jiandong Guo*\, and Jimin Zhao*\, Second harmonic generation in AB-type LaTiO3/SrTiO3 superlattices\, Nano Energy 82\, 105752 (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/jimin-zhao-ultraweak-electron-phonon-coupling-strength-in-cubic-boron-arsenide-unveiled-by-ultrafast-dynamics/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T101500 DTEND;TZID=Europe/Ljubljana:20211213T104500 DTSTAMP:20260810T010855 CREATED:20211201T212913Z LAST-MODIFIED:20211210T102900Z UID:1882-1639390500-1639392300@nqw.ijs.si SUMMARY:Coffee break DESCRIPTION: URL:https://nqw.ijs.si/event/coffe-break/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T104400 DTEND;TZID=Europe/Ljubljana:20211213T115900 DTSTAMP:20260810T010855 CREATED:20211207T103139Z LAST-MODIFIED:20211211T114045Z UID:2140-1639392240-1639396740@nqw.ijs.si SUMMARY:Chair: Tomaž Mertelj DESCRIPTION: URL:https://nqw.ijs.si/event/chair-zala-lenarcic/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T104500 DTEND;TZID=Europe/Ljubljana:20211213T111000 DTSTAMP:20260810T010855 CREATED:20211201T213330Z LAST-MODIFIED:20211214T082053Z UID:1901-1639392300-1639393800@nqw.ijs.si SUMMARY:Viktor Kabanov: Phonons in metals and Eliashberg function 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/viktor-kabanov-phonons-in-metals-and-eliashberg-function/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T111000 DTEND;TZID=Europe/Ljubljana:20211213T113500 DTSTAMP:20260810T010855 CREATED:20211201T213719Z LAST-MODIFIED:20211214T082119Z UID:1917-1639393800-1639395300@nqw.ijs.si SUMMARY:John Goold: Taking the temperature of a pure quantum state 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/john-goold-tba/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T113500 DTEND;TZID=Europe/Ljubljana:20211213T120000 DTSTAMP:20260810T010855 CREATED:20211201T213603Z LAST-MODIFIED:20211214T082147Z UID:1912-1639395300-1639396800@nqw.ijs.si SUMMARY:Rok Žitko: Universal Magnetic Oscillations of dc Conductivity in the Incoherent Regime of Correlated Systems DESCRIPTION:J. Vučičević\,1 R. Žitko2\,3 \n1Scientific Computing Laboratory\, Center for the Study of Complex Systems\, Institute of Physics Belgrade\, University of Belgrade\, Pregrevica 118\, 11080 Belgrade\, Serbia \n2Jožef Stefan Institute\, Jamova 39\, SI-1000 Ljubljana\, Slovenia \n3Faculty of Mathematics and Physics\, University of Ljubljana\, Jadranska 19\, SI-1000 Ljubljana\, Slovenia \nUsing the dynamical mean field theory we investigate the magnetic field dependence of dc conductivity in the Hubbard model on the square lattice\, fully taking into account the orbital effects of the field introduced via the Peierls substitution. In addition to the conventional Shubnikov–de Haas quantum oscillations\, associated with the coherent cyclotron motion of quasiparticles and the presence of a well-defined Fermi surface\, we find an additional oscillatory component with a higher frequency that corresponds to the total area of the Brillouin zone. These paradigm-breaking oscillations appear at elevated temperature. This finding is in excellent qualitative agreement with the recent experiments on graphene superlattices. We elucidate the key roles of the off-diagonal elements of the current vertex and the incoherence of electronic states\, and explain the trends with respect to temperature and doping. \n\nJ. Vučičević and R. Žitko\, “Universal magnetic oscillations of dc conductivity in the incoherent regime of correlated systems\,” Phys. Rev. Lett. 127\, 196601 (2021).\nJ. Vučičević and R. Žitko\, “Electrical conductivity in the Hubbard model: Orbital effects of magnetic field\,” Phys. Rev. B 104\, 205101 (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/rok-zitko-universal-magnetic-oscillations-of-dc-conductivity-in-the-incoherent-regime-of-correlated-systems/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T120000 DTEND;TZID=Europe/Ljubljana:20211213T163000 DTSTAMP:20260810T010855 CREATED:20211201T212913Z LAST-MODIFIED:20211207T124819Z UID:1883-1639396800-1639413000@nqw.ijs.si SUMMARY:Lunch DESCRIPTION: URL:https://nqw.ijs.si/event/lunch/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T162900 DTEND;TZID=Europe/Ljubljana:20211213T180900 DTSTAMP:20260810T010855 CREATED:20211207T103643Z LAST-MODIFIED:20211207T103643Z UID:2143-1639412940-1639418940@nqw.ijs.si SUMMARY:Chair: Peter Prelovšek DESCRIPTION: URL:https://nqw.ijs.si/event/chair-peter-prelovsek/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T163000 DTEND;TZID=Europe/Ljubljana:20211213T165500 DTSTAMP:20260810T010855 CREATED:20211201T213734Z LAST-MODIFIED:20211214T084244Z UID:1925-1639413000-1639414500@nqw.ijs.si SUMMARY:Fulvio Parmigiani: Time-resolved ARPES: a glance to the past-present-future 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/fulvio-parmigiani-time-revolved-arpes-a-glance-to-the-past-present-future/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T165500 DTEND;TZID=Europe/Ljubljana:20211213T172000 DTSTAMP:20260810T010855 CREATED:20211201T213346Z LAST-MODIFIED:20211214T084308Z UID:1903-1639414500-1639416000@nqw.ijs.si SUMMARY:Dragan Mihailovic: Quantum billiards in metastable heterostructures 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/dragan-mihailovic-quantum-billiards-in-metastable-heterostructures/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T172000 DTEND;TZID=Europe/Ljubljana:20211213T174500 DTSTAMP:20260810T010855 CREATED:20211201T213346Z LAST-MODIFIED:20211214T084337Z UID:1904-1639416000-1639417500@nqw.ijs.si SUMMARY:Janez Bonča: Relaxation mechanisms in a disordered system with the Poisson level statistics DESCRIPTION:Janez Bonča1\,2 and Marcin Mierzejewski3 \n1Department of Physics\, Faculty of Mathematics and Physics\, \nUniversity of Ljubljana\, SI-1000 Ljubljana\, Slovenia \n2Department of Theoretical Physics\, J. Stefan Institute\, SI-1000 Ljubljana\, Slovenia \n3Department of Theoretical Physics\, Faculty of Fundamental Problems of Technology\, \nWrocław University of Science and Technology\, 50-370 Wrocław\, Poland \nI will discuss the interplay between many-body localization and spin-symmetry. I will present the time evolution of several observables in the anisotropic t − J model. Like the Hubbard chain\, the studied model contains charge and spin degrees of freedom. Yet\, it has a smaller Hilbert space and thus allows for numerical studies of larger systems. I will compare the field disorder that breaks the Z2 spin symmetry and a potential disorder that preserves the latter symmetry. In the former case\, sufficiently strong disorder leads to localization of all studied observables\, at least for the studied system sizes. However\, in the case of symmetry-preserving disorder\, we observe that odd operators under the Z2 spin transformation relax towards the equilibrium value at relatively short time scales that grow only polynomially with the disorder strength. On the other hand\, the dynamics of even operators and the level statistics within each symmetry sector are consistent with localization. Our results indicate that localization exists within each symmetry sector for symmetry preserving disorder. Odd operators’ apparent relaxation is due to their time evolution between various symmetry sectors. \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/janez-bonca-relaxation-mechanisms-in-a-disordered-system-with-the-poisson-level-statistics/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T174500 DTEND;TZID=Europe/Ljubljana:20211213T181000 DTSTAMP:20260810T010855 CREATED:20211201T213346Z LAST-MODIFIED:20211214T084406Z UID:1905-1639417500-1639419000@nqw.ijs.si SUMMARY:Patrycja Lydzba: Single-particle eigenstate thermalization in quantum-chaotic quadratic Hamiltonians DESCRIPTION:P. Łydżba\,1 Yicheng Zhang\,2 Marcos Rigol\,2 Lev Vidmar3\,4 \n1Department of Theoretical Physics\, Wroclaw University of Science and Technology\, 50-370 Wrocław\, Poland \n2Department of Physics\, The Pennsylvania State University\, University Park\, Pennsylvania 16802\, USA \n3Department f Theoretical Physics\, J. Stefan Institute\, SI-1000 Ljubljana\, Slovenia \n4Department of Physics\, Faculty of Mathematics and Physics\, University of Ljubljana\, SI-1000 Ljubljana\, Slovenia \nIn this presentation\, we study single-particle properties of quantum-chaotic quadratic models\, which are identified with quadratic models having random matrix theory correlations in single-particle spectra\, i.e.\, exhibiting single-particle quantum chaos. We analyze matrix elements of local and nonlocal operators in two paradigmatic Hamiltonians\, i.e.\, the quadratic Sachdev-Ye-Kitaev model and the three-dimensional Anderson model below the localization transition. We demonstrate that their matrix elements display single-particle eigenstate thermalization. Specifically\, we show that the diagonal matrix elements exhibit vanishing eigenstate-to-eigenstate fluctuations\, and the variance proportional to the inverse Hilbert space dimension. We also demonstrate that the ratio between the variance of diagonal and off-diagonal matrix elements agrees with the prediction of random matrix theory. We also study distributions of matrix elements\, and establish the conditions under which they are (not) Gaussian. \n\nP. Łydżba et al. Phys. Rev. Lett. 125\, 180604 (2020)\nP. Łydżba et al. Phys. Rev. B 103\, 104206 (2021)\nP. Łydżba et al. arXiv:2109.06895 (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/patrycja-lydzba-single-particle-eigenstate-thermalization-in-quantum-chaotic-quadratic-hamiltonians/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T181000 DTEND;TZID=Europe/Ljubljana:20211213T200000 DTSTAMP:20260810T010855 CREATED:20211201T212913Z LAST-MODIFIED:20211201T212913Z UID:1884-1639419000-1639425600@nqw.ijs.si SUMMARY:Dinner DESCRIPTION: URL:https://nqw.ijs.si/event/dinner-2/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T195900 DTEND;TZID=Europe/Ljubljana:20211213T210000 DTSTAMP:20260810T010855 CREATED:20211207T114616Z LAST-MODIFIED:20211210T134751Z UID:2162-1639425540-1639429200@nqw.ijs.si SUMMARY:Chair: Anže Mraz DESCRIPTION: URL:https://nqw.ijs.si/event/chair-janez-bonca/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T200000 DTEND;TZID=Europe/Ljubljana:20211213T202500 DTSTAMP:20260810T010855 CREATED:20211201T213734Z LAST-MODIFIED:20211214T084848Z UID:1926-1639425600-1639427100@nqw.ijs.si SUMMARY:Mariano Trigo: Topological defects on demand in the charge density wave of SmTe3 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/mariano-trigo-zoom-california-topological-defects-on-demand-in-the-charge-density-wave-of-smte3/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T202500 DTEND;TZID=Europe/Ljubljana:20211213T204000 DTSTAMP:20260810T010855 CREATED:20211201T213848Z LAST-MODIFIED:20211214T084910Z UID:1941-1639427100-1639428000@nqw.ijs.si SUMMARY:Manuel Tuniz: Non-equilibrium electron dynamics of the bulk VSe2 charge-density-wave system DESCRIPTION:Wibke Bronsch\,1 Manuel Tuniz\,2 Denny Puntel\,2 Alessandro Giammarino\,2 Fulvio Parmigiani1\,2 and Federico Cilento1 \n1Elettra – Sincrotrone Trieste S.C.p.A.\, Italy \n2Dipartimento di Fisica\, Università degli Studi di Trieste\, Italy \nBy means of time- and angle-resolved photoemission spectroscopy (tr-ARPES)\, we investigate the effect of the charge density wave (CDW) phase transition on the equilibrium and out-ofequilibrium electronic properties of the transition metal dichalcogenide VSe2. The electronic band structure of VSe2 has recently been subject of investigation ranging from the bulk to the monolayer regime\, in search for the manifestation of the opening of the band gap in its CDW phase [1\,2]. However\, at present\, only a few studies on the effect of an ultrafast optical excitation are available [1\,3]. In our contribution we present a study on the bulk material. By selecting the polarization of the probe pulses\, tr-ARPES allows us to disentangle states with different orbital character\, originating from the V and Se valence bands. When moving across the critical temperature of the CDW phase transition\, our tr-ARPES data show indication for a change in the fast relaxation dynamics and for a different filling of novel photoinduced states near the Fermi level\, lasting for several picoseconds after photoexcitation. \n\nBiswas et al.\, Nano Letters 21\, 1968-1975 (2021).\nUmemoto et al.\, Nano Research 12\, 165-169 (2019).\nMajchrzak et al.\, arXiv:2011.06358v1 (2020).\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/manuel-tuniz-non-equilibrium-electron-dynamics-of-the-bulk-vse2-charge-density-wave-system/ CATEGORIES:NQW 2021 END:VEVENT BEGIN:VEVENT DTSTART;TZID=Europe/Ljubljana:20211213T204000 DTEND;TZID=Europe/Ljubljana:20211213T205500 DTSTAMP:20260810T010856 CREATED:20211201T213903Z LAST-MODIFIED:20211214T084936Z UID:1942-1639428000-1639428900@nqw.ijs.si SUMMARY:Gregor Jecl: Optical signatures of photoinduced phase transitions in IrTe2 DESCRIPTION:G. Jecl\,1\,2* V. Nasretdinova\,3 Y. Gerasimenko\,1\,† T. Mertelj\,1\,2 C. Monney\,4 F. von Rohr\,5 D. Mihailović1\,2\,3 \n1Department of Complex Matter\, Jožef Stefan Institute\, Ljubljana\, SI-1000\, Slovenia \n2Faculty of Mathematics and Physics\, University of Ljubljana\, Ljubljana\, SI-1000\, Slovenia \n3CENN Nanocenter\, Ljubljana\, SI-1000\, Slovenia \n4Département de Physique and Fribourg Center for Nanomaterials\, Université de Fribourg\, Fribourg\, CH-1700\, Switzerland \n5Department of Chemistry\, University of Zürich\, Zürich\, CH-8057\, Switzerland \nIrTe2\, a Van-der-Waals transition metal dichalcogenide\, is known to host a complicated phase diagram: two first order phase transitions into charge ordered stripe phases of different periodicity are observed in bulk undoped samples [1]; superconductivity emerges in bulk doped samples resulting in the familiar superconducting dome behavior [1]; superconductor – normal metal switching was demonstrated in un-doped quenched nanoflakes [2]; and superconductivity has been shown to emerge in thin flakes resulting in a superconducting dome as a function of flake thickness [3]. Most interestingly however\, fast cooling of undoped bulk samples has resulted in the formation of superconducting hexagonal-like surface patches appearing at three-fold stripe phase intersections [4]. \nWe have studied the possibility to control the low temperature charge order in IrTe2 with ultrafast pulses using optical time domain spectroscopy. High fluence photoexcitation gives rise to non-thermal behavior of transient reflectivity on sub-picosecond timescales\, indicative of a transient photoinduced phase transition thought to be associated with Ir dimer breaking and recovery [5]. Following the trajectory of the system in double-pump measurements we observe definite evidence of a transition to a mixture of higher temperature equilibrium phases several picoseconds after the arrival of the strongly perturbing pulse\, as well as the material’s subsequent relaxation into the low temperature equilibrium state some 100 to 150 picoseconds after excitation. We conclude that the phase transitions at these timescales are driven by the increase in the transient lattice temperature imposed by laser excitation. \nOn the other hand\, by tracking the response to increasing intensity of the pump beam at a fixed delay in the double-pump experiment we observe threshold-like behavior in the temporal as well as in the spectral domain\, thus shedding light on the connection between the dimer breaking transition at sub-picosecond timescales and the transient lattice temperature driven transitions at longer timescales. \n\nS. Pyon et.al.\, Journal of the Physical Society of Japan\, 81\, 053701 (2012)\nH. Oike at. al.\, Science Advances 4\, eaau3489\, 2018\nS. Park et.al.\, Nature Communications 12\, 3157\, 2021\nH. S. Kim et.al.\, Nano Letters\, 16\, 4620-4265\, 2016\nS.-I. Ideta et. al.\, Science Advances 4\, eaar3867\, 2018\n\n†Present affiliation: Faculty of Physics\, Universität Regensburg\, 93040 Regensburg\, Germany \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/gregor-jecl-optical-signatures-of-photoinduced-phase-transitions-in-irte2/ CATEGORIES:NQW 2021 END:VEVENT END:VCALENDAR