BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Unveiling the bosonic nature in an ultrashort single-electron puls e DTSTART;VALUE=DATE-TIME:20190619T163000Z DTEND;VALUE=DATE-TIME:20190619T170000Z DTSTAMP;VALUE=DATE-TIME:20261013T042850Z UID:indico-contribution-44-246@cern.ch DESCRIPTION:Speakers: Everton Arrighi (Institut Neel)\nQuantum dynamics is very sensitive to dimensionality. While two-dimensional electronic system s form Fermi liquids\, one-dimensional systems - Tomonaga-Luttinger liquid s - are described by purely bosonic excitations\, even though they are ini tially made of fermions. \nWith the advent of coherent single-electron sou rces [1- 3]\, the quantum dynamics of such a liquid is now accessible at t he single-electron level. Very little is known\, however\, on the propagat ion of such single electron charge excitations.\nHere\, we investigate in a time-resolved manner the propagation of an ultrashort single-electron ch arge pulse injected into a quasi-one-dimensional quantum conductor. This a llows us to extract the collective\ncharge excitation velocity. We show th at the velocity of such a single electron pulse is found to be much faster than the Fermi velocity due to the presence of strong electron-electron i nteractions and can be tuned over more than an order of magnitude by elect rostatic confinement. In addition\, our set-up allows us to tune our syste m continuously from a clean one-channel Tomonaga-Luttinger liquid to a mul ti-channel Fermi liquid. Our results [4] are in quantitative agreement wit h a parameter-free theory and demonstrate a powerful new probe for directl y investigating real-time dynamics of fractionalisation phenomena in low-d imensional conductors.\n[1] G. Fève\, A. Mahé\, J.-M. Berroir\, T. Konto s\, B. Plaçais\, D.C. Glattli\, A. Cavanna\, B. Etienne\, Y. Jin. “An O n-Demand Coherent Single-Electron Source”. Science 316\, 1169-1172 (2007 ).\n[2] J. Dubois\, T. Jullien\, F. Portier\, P. Roche\, A. Cavanna\, Y. J in\, W. Wegscheider\, P. Roulleau and D.C. Glattli. “Minimal-excitation states for electron quantum optics using levitons.”\, Nature 502\, 659-6 63 (2013)\n[3] C. Bäuerle\, C. Glattli\, T. Meunier\, F. Portier\, P. Roc he\, P. Roulleau\, S. Takada\, and X. Waintal\, “Coherent control of sin gle electrons: a review of current progress”\, Rep. Prog. Phys (2018) DO I: 10.1088/1361-6633/aaa98a\n[4] G. Roussely\, E. Arrighi\, G. Georgiou\, S. Takada\, M. Schalk\, M. Urdampilleta\, A. Ludwig\, A. D. Wieck\, P. Arm agnat\, T. Kloss\, X. Waintal\, T. Meunier\, and C. Bauerle. Unveiling the bosons in an ultra-short single electron pulse\, Nature Communications 9\ , 2811 (2018)\n\nhttps://indico.unina.it/event/18/contributions/246/ LOCATION:Strand Hotel Terme Delfini URL:https://indico.unina.it/event/18/contributions/246/ END:VEVENT BEGIN:VEVENT SUMMARY:Elusive Bose metal is a Bosonic Topological Insulator DTSTART;VALUE=DATE-TIME:20190619T153000Z DTEND;VALUE=DATE-TIME:20190619T160000Z DTSTAMP;VALUE=DATE-TIME:20261013T042850Z UID:indico-contribution-44-221@cern.ch DESCRIPTION:Speakers: Valerii Vinokur (Argonne National Laboratory)\nTrans port measurements of the superconductor-insulator transition (SIT) in diso rdered two-dimensional films and Josephson junction arrays showed the exis tence of an anomalous metallic phase that persists to low temperatures. Th e nature of this mysterious phase often referred to as “Bose metal\,” remains unclear. We develop a gauge theory of the Bose metal as the phase in which Cooper pairs and vortices are out of the Bose condensate due to s trong quantum fluctuations and form an incompressible liquid of intertwine d Aharonov-Bohm-Casher loops. As a result\, the Bose metal emerges as an i nteger (Z) bosonic topological insulator in which bulk transport is suppre ssed by topological mutual statistics interactions\, the Hall resistance v anishes\, and longitudinal charge transport is mediated by U(1)-symmetry-p rotected gapless edge modes. The transport measurements in NbTiN films acr oss the disorder- and magnetic field-driven SIT and observe a disorder and magnetic field–tuned transition from a true superconductor to a metalli c phase with saturated longitudinal resistivity.\n\nhttps://indico.unina.i t/event/18/contributions/221/ LOCATION:Strand Hotel Terme Delfini URL:https://indico.unina.it/event/18/contributions/221/ END:VEVENT BEGIN:VEVENT SUMMARY:Coherent effects in junctions based on p-wave superconductor DTSTART;VALUE=DATE-TIME:20190619T150000Z DTEND;VALUE=DATE-TIME:20190619T153000Z DTSTAMP;VALUE=DATE-TIME:20261013T042850Z UID:indico-contribution-44-201@cern.ch DESCRIPTION:Speakers: Alexander Golubov (Moscow Institute of Physics and T echnology\, Dolgoprudny\, Russia\, and Faculty of Science and Technology\, University of Twente\, Enschede\, The Netherlands)\nThe famed p-wave supe rconductivity harbors a variety of exotic topological states. The practica l ways for its implementing are being extensively discussed in literature\ , and the contact of a superconductor with the topological insulator is ex pected to become the most promising candidate. There have been reports of the 4π-periodicity in such contacts\, which are a hallmark of the p-wave superconductivity. However\, the phase-sensitive measurements of the Josep hson currents that would serve as conclusive evidence of the p-wave symmet ry are still lacking. In this work we report direct observation of the Jos ephson effect in the Nb/Bi2Te2Se/Nb structures which are characterized by ballistic electronic transport across the Bi2Te2Se nanocrystals. We show t hat in the mK temperature range the investigated junctions exhibit a new t ype of oscillations of the Josephson current in magnetic field with an ult ra-short period ∼ 1 Oe corresponding to energy spectrum with the level s pacing of order of 1 µeV. We develop theoretical model explaining these o scillations in terms of fine structure of low-energy Andreev bound states. The results are consistent with emerging p-wave superconducting correlati ons induced at the Bi2Te2Se surface due to an interplay between the s-wave superconductivity in Nb and a peculiar symmetry of the topological insula tor Bi2Te2Se. This work is supported by the Russian Science Foundation (P roject No. 18-72-10118)\, the EU H2020-WIDESPREAD-05-2017-Twinning project “SPINTECH” (the Grant Agreement No. 810144) and by Dutch FOM.\n\nhttp s://indico.unina.it/event/18/contributions/201/ LOCATION:Strand Hotel Terme Delfini URL:https://indico.unina.it/event/18/contributions/201/ END:VEVENT BEGIN:VEVENT SUMMARY:Topological Superconductivity in Non-Centrosymmetric Materials DTSTART;VALUE=DATE-TIME:20190619T160000Z DTEND;VALUE=DATE-TIME:20190619T163000Z DTSTAMP;VALUE=DATE-TIME:20261013T042850Z UID:indico-contribution-44-222@cern.ch DESCRIPTION:Speakers: Matthias Eschrig (Royal Holloway\, University of Lon don)\nRecent interest in the effect of intrinsic spin-orbit coupling in ma terials that exhibit an excitation gap has led to the notions of topologic al insulators and topological superconductors. Intrinsic spin-orbit coupli ng is enhanced in non-centrosymmetric materials\, as in this case already band-diagonal matrix elements contribute. We study non-centrosymmetric sup erconductors with various point group symmetries. For self-consistent orde r parameter profiles we calculate the surface density of states\, showing intricate structure of spin-polarised Andreev bound states. The topology ’s effect on the surface states and the tunnel conductance is thoroughly investigated\, and a topological phase diagram is constructed for open an d closed Fermi surfaces showing a sharp transition between the two for the cubic point group O.\n\nhttps://indico.unina.it/event/18/contributions/22 2/ LOCATION:Strand Hotel Terme Delfini URL:https://indico.unina.it/event/18/contributions/222/ END:VEVENT END:VCALENDAR