Moscow Institute of Physics and Technology

Theoretical nanophysics laboratory (laboratory is closed since 31.12.2016)

Upcoming quantum-nanophysics seminars
colloquium, Friday, October 25, 2019, , 11:30 am

Yuval Gefen (Weizmann Institute of Science, Israel)

Physics at the Edge of a QHE setting

The structure of the edge of a QHE edge is constrained, but not dictated, by the topology of the bulk. Particularly interesting is the class of hole-conjugate fractional QH states. For such states the edge hosts counter-propagating modes that are responsible for quantized electrical and thermal conductance. In the coherent quantum limit renormalized edge modes emerge, which may involve neutral modes with non-trivial exchange statistics. I will discuss the behavior of topology-influenced transport coefficient both in the coherent and the fully equilibrated regimes, topological classification of non-equilibrium shot noise, and the relation to recent experiments.

Scientific Council of the Landau Institute, Friday, October 25, 2019, Landau Institute, 3:00 pm

Yan V. Fyodorov (Dept. of Mathematics, King’s College London)

Zeroes of S-matrix entries and random 'anti-lasing'

Motivated by recent experimental interest in 'random anti-lasing' (e.g. K. Pichler et al. Nature 567, 351 (2019)) I consider manifestations of zeroes of scattering matrices in wave-chaotic cavities. In particular, I will introduce the notion of Reflection Time Difference playing the same role for the S-matrix zeroes as the Wigner time delay plays for the S-matrix poles, and a possibility of its experimental measurement. I will then discuss how statistics of complex zeroes of scattering matrix entries can be described in the framework of RMT-based model of resonance scattering.
Presentation will be based on papers arXiv:1908.06920 and J. Phys. A 50, 30LT01 (2017).

Visiting address:

Laboratory building, room 122
Moscow Institute of Physics and Technology
Dolgoprudny, Russia

contact e-mail address: nanotheory@phystech.edu (head M.V.Feigel'man, deputy head I.V.Zagorodnev)

Research topics
  • Mesoscopic electronic systems
  • Superconducting hybrid structures
  • Quantum phase transitions
  • Spintronics
  • 2DEG and quantum Hall effect
  • Quantum magnetism and topological order
  • Physics of quantum computation
Recent quantum-nanophysics seminars
Scientific Council of the Landau Institute, Friday, October 11, 2019, Landau Institute, 11:30 am

Ya.V. Fominov

Konferentsiya NANO-2019: Limits of Nanoscience and Nanotechnologies

Otchet ob uchastii v konferentsii "NANO-2019: Limits of Nanoscience and Nanotechnologies" (Kishinev, Moldaviya).

Scientific Council of the Landau Institute, Friday, October 11, 2019, Landau Institute, 11:30 am

Ya.V. Fominov

Sverkhprovodyashchie tripletnye spinovye klapany tipa FFS so splavom Geislera v kachestve odnogo iz ferromagnitnykh sloev

Provedeno teoreticheskoe soprovozhdenie novoi serii eksperimentov po izucheniyu effekta sverkhprovodyashchego tripletnogo spinovogo klapana v sisteme tipa FFS (gde F — ferromagnetik, S — sverkhprovodnik). Effekt sostoit v tom, chto kriticheskaya temperatura Tc sistemy zavisit ot vzaimnoi orientatsii namagnichennostei dvukh ferromagnetikov. V eksperimente v kachestve srednego ili vneshnego F sloya byl vzyat splav Geislera Co2Cr1-xFexAl, magnitnye svoistva kotorogo zaviseli ot uslovii prigotovleniya. Dlya ob'yasneniya poluchennykh rezul'tatov byla sformulirovana teoriya, uchityvayushchaya proizvol'nye obmennye polya F sloev i proizvol'nye parametry granits v ramkakh kvaziklassiki v diffuznom predele.
Doklad osnovan na sleduyushchikh rabotakh:
[1] A.A. Kamashev, N.N. Garif’yanov, A.A. Validov, J. Schumann, V. Kataev, B. Büchner, Ya.V. Fominov, I.A. Garifullin, "Superconducting switching due to a triplet component in the Pb/Cu/Ni/Cu/ Co2Cr1-xFexAl y spin-valve structure", Beilstein J. Nanotechnol. 10, 1458 (2019).
[2] A.A. Kamashev, N.N. Garif’yanov, A.A. Validov, J. Schumann, V. Kataev, B. Büchner, Ya.V. Fominov, I.A. Garifullin, "Superconducting spin-valve effect in heterostructures with ferromagnetic Heusler alloy layers", napravleno v Phys. Rev. B.