A5104593272- Advanced Frequency and Time Standards
- Quantum and electron transport phenomena
- Graphene research and applications
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Spectroscopy and Quantum Chemical Studies
- Laser-Matter Interactions and Applications
- Geophysics and Sensor Technology
- Quasicrystal Structures and Properties
- Topological Materials and Phenomena
- Scientific Measurement and Uncertainty Evaluation
- Molecular Junctions and Nanostructures
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Chemical Physics Studies
- Quantum optics and atomic interactions
- Advanced Condensed Matter Physics
- Gyrotron and Vacuum Electronics Research
- Spectroscopy and Laser Applications
- Intermetallics and Advanced Alloy Properties
- Optical and Acousto-Optic Technologies
- Microfluidic and Bio-sensing Technologies
- Astronomical Observations and Instrumentation
- Advanced Research in Systems and Signal Processing
- Mechanical and Optical Resonators
- Advanced Electrical Measurement Techniques
The University of Texas at Austin
2022-2023
All-Russian Scientific Research Institute of Physical-Technical and Radiotechnical Measurements
2012-2019
Russian Quantum Center
2017-2018
Moscow Institute of Physics and Technology
2014-2017
Rosinformagrotekh
2012
Lightly doped multilayer graphene surprised researchers with the emergence of superconductivity and magnetism under strong electric displacement fields. The authors interpret field versus hole-density phase diagram using mean-field theory experimentally informed band structure. They find that in these electronic systems is often intertwined nematic order because noncompact Fermi sea topology fourfold spin-valley degeneracy.
We employ a functional renormalization group approach to ascertain the pairing mechanism and symmetry of superconducting phase observed in rhombohedral trilayer graphene. Superconductivity this system occurs regime carrier density displacement field with weakly distorted annular Fermi sea. find that repulsive Coulomb interactions can induce electron on surface by taking advantage momentum-space structure associated finite width sea annulus. The degeneracy between spin-singlet spin-triplet is...
Abstract A new method for finding electronic structure and wavefunctions of electrons in quasiperiodic potential is introduced. To obtain results it uses slightly modified Schrödinger equation spaces dimensionality higher than physical space. It enables to get exact quasicrystals without expensive non-exact calculations.
The paper presents results of development programs just finished in VNIIFTRI. Some them, such as CS fountain standard, ensemble new H-masers and TWSTFT station, directly improved the State Time Frequency Standard Russia, influence other are expected closest future.
We investigate the possibility and implications of interlayer coherence in electrically isolated superconducting bilayers. find that a mean-field approximation bilayers can have excitonic order simultaneously if repulsive interactions between layers are sufficiently strong. The implies phase be studied representation symmetric antisymmetric bilayer states. When both orders present we several solutions equations with different values state pair amplitudes. mixed necessarily has nonzero...
We study the time evolution of a half-filled Hubbard layer coupled to magnon bath after quench interaction. Qualitatively different regimes, regarding asymptotic long-time dynamics, are identified and characterized within mean-field approximation. In absence bath, dynamics closed system is similar that quenched BCS condensate. Though presence introduces an additional relaxation mechanism, our numerical results analytical arguments show equilibration with not necessarily attained...
At previous PTTI meeting, PTTI'17, we mentioned that VNIIFTRI has got four Rb fountain frequency standards, which run as not clocks. These instruments are intended for secondary presentation of the time unit second SI. indeed very stable reference without drift inherent, example, to H-masers. During last year output these standards been calibrated against operational CsF02 primary standard and now one may use keepers. This report will present preliminary results first experiments on...
AOM-RN, a compact acousto-optic modulator operating purely in the Raman-Nath diffraction regime, extended tools employed laser spectroscopy as optical phase modulators. We report AOM-RN capacity to be pump-probe modulation transfer atomic vapors.
We employ a functional renormalization group approach to ascertain the pairing mechanism and symmetry of superconducting phase observed in rhombohedral trilayer graphene. Superconductivity this system occurs regime carrier density displacement field with weakly distorted annular Fermi sea. find that repulsive Coulomb interactions can induce electron on surface by taking advantage momentum-space structure associated finite width sea annulus. The degeneracy between spin-singlet spin-triplet is...
A remote comparison campaign of Caesium fountain clocks from four National Metrology Institutes in Europe and Asia was carried out May 2013. Six fountains at Physikalisch-Technische Bundesanstalt (PTB) Germany, Scientific Research Institute Physical-Technical Radio Technical Measurements (VNIIFTRI-SU) Russia, Physical Laboratory India (NPLI) (NIM) China were compared by Two-Way Satellite Time Frequency Transfer (TWSTFT) GPS Carrier Phase (GPS CP) techniques. The frequency differences the...
This paper outlines the evolution of stand alone cavity auto tuning active hydrogen maser using microwave frequency switching technique. Analysis basic destabilizing factors limiting short- term, long- term stability and phase noise output signal this technique is given. The effect on short medium characteristics negligible. Long-term (3÷5) × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-16</sup> at averaging time 1÷20 days has been achieved.
This report presents two main aspects of the VNIIFTRI Department Metrology for Time and Space functions. First changes in operational activity to maintain national time unit scale. Then results investigation development program improve frequency standard including new generation H-masers, Rb fountain standards, 87Sr neutral atoms an optical lattice standard, transfer techniques based on different technologies such as TWSTFT, fiber, laser ranging.
We provide a complete theoretical interpretation of the metallic broken spin/valley symmetry states recently discovered in ABC trilayer graphene (ABC) perturbed by large transverse displacement field. Our conclusions combine insights from electronic structure models and mean field theory, are guided precise magneto-oscillation Fermi-surface-area measurements. conclude that physics is shaped principle momentum-space condensation, which favors Fermi surface reconstructions enabled flavor...
Last year during PTTI 2020 we delivered special talk on timing problems in Russia connections with coming continuous UTC changes [1]. Today, one later, understand this step considerably better – inside situation looks like stick unthill. Many governmental agencies and ministries, first of all the State Service for Time Frequency, Roscosmos Ministry Defense Russian Federation, are rush. We started that time penetrates aspects our live activities will need too much time, resources investment....
According to GLONASS ICD [1] UTC(SU) is a reference time scale for System Time (GLO ST). That’s why one of continuous tasks VNIIFTRI monitor actual difference between and GLO ST conformity this value the ?c = + 03h00m ST, broadcasted in navigation message. started such monitoring since end 80th [2, 3]. Ever that time, have been used many receiver’s type monitoring. Each step receiver change included relative calibration procedure maintain – continuous. Now we use TTS3, TTS4 receivers...
A new method for finding electronic structure and wavefunctions of electrons in quasiperiodic potential is introduced. To obtain results it uses slightly modified Schrodinger equation spaces dimensionality higher than physical space. It enables to get exact quasicrystals without expensive non-exact calculations. New tested on one-dimensional screened Coulomb potential.
At a large displacement field, in rhomboedral and Bernal-stacked graphene normal paramagnetic state transitions to correlated state. Recent experiments showed that such systems have several phase as function of the carrier density. The adjacent has anomalously high resistance reduced degeneracy Fermi sea. We show both phenomena can be explained through concept partial intervalley exciton condensation: fraction particles condenses into excitons, another forms an coherent liquid. part system...
The advent of attosecond spectroscopy, in particular high harmonic generation has led to advances following electronic dynamics atoms and molecules on their natural timescale. recent discovery the bulk solids opened door for applying HHG spectroscopy ultrafast investigations condensed phase, including demonstration dynamical Bloch oscillations, analysis relative importance intraband interband current generation, reconstruction band structure ZnO. In particular, work elegantly demonstrated...
The work presents a study of CPT-based atomic clocks with miniature rubidium vapour cells fabricated by direct optical bonding (DOB). This MEMS-compatible technology was for the first time used making containing alkali-metal vapour. One its important advantages is relatively low temperature (e.g. room temperature) required cell assembly. discusses results spectral measurements DOB-fabricated volume less than 1 cm<sup>3</sup> , which provided stability better 5·10<sup>–11</sup> at second and...