457 research outputs found
Bistability and Hysteresis of Intersubband Absorption in Strongly Interacting Electrons on Liquid Helium
We study nonlinear inter-subband microwave absorption of electrons bound to
the liquid helium surface. Already for a comparatively low radiation intensity,
resonant absorption due to transitions between the two lowest subbands is
accompanied by electron overheating. The overheating results in a significant
population of higher subbands. The Coulomb interaction between electrons causes
a shift of the resonant frequency, which depends on the population of the
excited states and thus on the electron temperature . The latter is
determined experimentally from the electron photoconductivity. The
experimentally established relationship between the frequency shift and
is in reasonable agreement with the theory. The dependence of the shift on the
radiation intensity introduces nonlinearity into the rate of the inter-subband
absorption resulting in bistability and hysteresis of the resonant response.
The hysteresis of the response explains the behavior in the regime of frequency
modulation, which we observe for electrons on liquid He and which was
previously seen for electrons on liquid He
Climate variations in the Northern Hemisphere based on the use of an atmosphere-ocean IPCC model
Forced and natural variability of modelled and observed Atlantic Ocean temperature and Atlantic Meridional Overturning Circulation (AMOC) is studied. In the observations and in a forced climate model run, we find increasing temperature at 1000m in the Atlantic (20N). SVD analysis shows that, for both model data and observations, a high index of North Atlantic Oscillation (NAO) corresponds
to negative temperature anomaly at 1000m to the north of 55N, although geographical details of temperature anomaly distribution are different for the model and observations. Particular attention has been paid to the influence of the fresh water flux due to the present global warning on the slowing down of the AMOC. It is shown that fresh water flux change is only a secondary cause of reduced AMOC in global warming conditions, while heat flux change is probably the main reason. Finally, it is shown that internal model AMOC variability is positively correlated with the near-surface air temperature in Atlantic-European Arctic sector on a
10-year time scale
Electric field induced strong localization of electrons on solid hydrogen surface: possible applications to quantum computing
Two-dimensional electron system on the liquid helium surface is one of the
leading candidates for constructing large analog quantum computers (P.M.
Platzman and M.I. Dykman, Science 284, 1967 (1999)). Similar electron systems
on the surfaces of solid hydrogen or solid neon may have some important
advantages with respect to electrons on liquid helium in quantum computing
applications, such as larger state separation , absence of
propagating capillary waves (or ripplons), smaller vapor pressure, etc. As a
result, it may operate at higher temperatures. Surface roughness is the main
hurdle to overcome in building a realistic quantum computer using these states.
Electric field induced strong localization of surface electrons is shown to be
a convenient tool to characterize surface roughness.Comment: 4 pages, 3 figure
The effect of the probe magnetic moment orientation of magnetic resonance force microscope on the spectra of spin wave resonances
This work was supported by the Russian Science Foundation (project 16-12-10254)
Amplification of Fluctuations in Unstable Systems with Disorder
We study the early-stage kinetics of thermodynamically unstable systems with
quenched disorder. We show analytically that the growth of initial fluctuations
is amplified by the presence of disorder. This is confirmed by numerical
simulations of morphological phase separation (MPS) in thin liquid films and
spinodal decomposition (SD) in binary mixtures. We also discuss the
experimental implications of our results.Comment: 15 pages, 4 figure
Realizability of Polytopes as a Low Rank Matrix Completion Problem
This article gives necessary and sufficient conditions for a relation to be
the containment relation between the facets and vertices of a polytope. Also
given here, are a set of matrices parameterizing the linear moduli space and
another set parameterizing the projective moduli space of a combinatorial
polytope
Π‘ΡΠ΅Π½Π°ΡΠΈΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊ ΡΠ°Π·Π²ΠΈΡΡΡ ΡΡΡΠ°Π½ ΠΈ Π ΠΎΡΡΠΈΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ ΠΏΠΎΡΡΠΏΠ°Π½Π΄Π΅ΠΌΠΈΠΈ
Amid the Kondratiev cycle's downward slope movement and global pandemic, a recession in many countries is Likely to Lead to a deep long-term economic crisis. The aim of the article is to study the simplest recession indicators in developing and developed countries, economic-recovery measures, and economic development scenarios. The objectives of the paper are to study current economic situations in different countries, including Russia; identify measures to prevent a recession in developing and developed countries; evaluate possible economic development scenarios with regard to the cyclical dynamics in the current climate. The authors used methods of analysis, modelling, monitoring of major economic indicators based on the data of past recessions and other crises. The results of the research show different scenarios of economic growth depending on the number of Covid-19 cases and the effectiveness of governmentβs responses to the pandemic; a correlation between monetary and fiscal policies in overcoming crisis; monetary policy priorities necessary for economic recovery; problems and prospects of monetary and fiscal policy implementation. The authors concluded that GDP, unemployment, and inflation rate are key indicators for the evaluation of the current and future money, credit, and production-related events. Proactive measures ensure a smoother average economic growth. Both monetary and fiscal policy have advantages and disadvantages. Proactive measures, in particular, inevitably cause two time lags: in the reaction to a recession and in the effectiveness of implemented measures. The governments and central banks must be proactive in overcoming the economic recession and providing support to the citizens.ΠΠ° ΡΠΎΠ½Π΅ ΠΏΠΎΠ½ΠΈΠΆΠ°ΡΠ΅Π»ΡΠ½ΠΎΠΉ Π²ΠΎΠ»Π½Ρ ΡΠΈΠΊΠ»Π° Π.Π. ΠΠΎΠ½Π΄ΡΠ°ΡΡΠ΅Π²Π° ΠΈ Π² ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΏΠ°Π½Π΄Π΅ΠΌΠΈΠΈ ΡΠ΅ΡΠ΅ΡΡΠΈΡ Π²ΠΎ ΠΌΠ½ΠΎΠ³ΠΈΡ
ΡΡΡΠ°Π½Π°Ρ
ΠΌΠΎΠΆΠ΅Ρ ΠΏΠ΅ΡΠ΅ΠΉΡΠΈ Π² Π³Π»ΡΠ±ΠΎΠΊΠΈΠΉ ΠΈ Π΄ΠΎΠ»Π³ΠΎΡΡΠΎΡΠ½ΡΠΉ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΠΊΡΠΈΠ·ΠΈΡ. Π¦Π΅Π»Ρ ΡΡΠ°ΡΡΠΈ - ΠΎΠΏΠΈΡΠ°ΡΡ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ ΠΏΠΎΠ½ΡΡΠ½ΡΠ΅ ΠΈΠ½Π΄ΠΈΠΊΠ°ΡΠΎΡΡ ΡΠ΅ΡΠ΅ΡΡΠΈΠΈ Π² ΡΠ°Π·Π²ΠΈΠ²Π°ΡΡΠΈΡ
ΡΡ ΠΈ ΡΠ°Π·Π²ΠΈΡΡΡ
ΡΡΡΠ°Π½Π°Ρ
, ΠΌΠ΅ΡΡ, ΠΏΡΠΈΠ½ΠΈΠΌΠ°Π΅ΠΌΡΠ΅ ΠΏΠΎ ΠΏΡΠ΅Π΄ΠΎΡΠ²ΡΠ°ΡΠ΅Π½ΠΈΡ ΡΠ΅ΡΠ΅ΡΡΠΈΠΈ ΠΈ ΠΎΡΠ΅Π½ΠΈΡΡ ΡΡΠ΅Π½Π°ΡΠΈΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ. ΠΠ»Ρ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ Π΄Π°Π½Π½ΠΎΠΉ ΡΠ΅Π»ΠΈ Π°Π²ΡΠΎΡΡ Π²ΡΠΏΠΎΠ»Π½ΠΈΠ»ΠΈ ΡΠ»Π΅Π΄ΡΡΡΠΈΠ΅ Π·Π°Π΄Π°ΡΠΈ: ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π»ΠΈ ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΠΎΠ΅ ΡΠΎΡΡΠΎΡΠ½ΠΈΠ΅ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊ ΡΠ°Π·Π½ΡΡ
ΡΡΡΠ°Π½, Π² ΡΠΎΠΌ ΡΠΈΡΠ»Π΅ Π ΠΎΡΡΠΈΠΈ; ΠΎΠΏΡΠ΅Π΄Π΅Π»ΠΈΠ»ΠΈ ΠΌΠ΅ΡΡ ΠΏΠΎ ΠΏΡΠ΅Π΄ΠΎΡΠ²ΡΠ°ΡΠ΅Π½ΠΈΡ ΡΠ΅ΡΠ΅ΡΡΠΈΠΈ Π² ΡΠ°Π·Π²ΠΈΡΡΡ
ΠΈ ΡΠ°Π·Π²ΠΈΠ²Π°ΡΡΠΈΡ
ΡΡ ΡΡΡΠ°Π½Π°Ρ
; ΡΠ°ΡΡΠΌΠΎΡΡΠ΅Π»ΠΈ ΡΡΠ΅Π½Π°ΡΠΈΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ Π² ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
Ρ ΡΡΠ΅ΡΠΎΠΌ ΡΠΈΠΊΠ»ΠΈΡΠ΅ΡΠΊΠΎΠ³ΠΎ Ρ
Π°ΡΠ°ΠΊΡΠ΅ΡΠ° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠΉ Π΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ. ΠΡΠΏΠΎΠ»ΡΠ·ΠΎΠ²Π°Π½Ρ ΠΌΠ΅ΡΠΎΠ΄Ρ Π°Π½Π°Π»ΠΈΠ·Π°, ΠΌΠΎΠ΄Π΅Π»ΠΈΡΠΎΠ²Π°Π½ΠΈΡ, ΠΌΠΎΠ½ΠΈΡΠΎΡΠΈΠ½Π³Π° ΠΎΡΠ½ΠΎΠ²Π½ΡΡ
ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΈΡ
ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»Π΅ΠΉ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΡΠ΅ΡΡΠΎΡΠΏΠ΅ΠΊΡΠΈΠ²Π½ΡΡ
Π΄Π°Π½Π½ΡΡ
, ΠΎΡ
Π²Π°ΡΡΠ²Π°ΡΡΠΈΡ
Π½Π΅ΡΠΊΠΎΠ»ΡΠΊΠΎ ΡΠ΅ΡΠ΅ΡΡΠΈΠΉ ΠΈ Π°Π½Π°Π»ΠΎΠ³ΠΈΠΈ. Π ΡΠ΅Π·ΡΠ»ΡΡΠ°ΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Ρ: ΠΏΡΡΠΈ ΡΠ°Π·Π²ΠΈΡΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ Π² Π·Π°Π²ΠΈΡΠΈΠΌΠΎΡΡΠΈ ΠΎΡ ΠΊΠΎΠ»ΠΈΡΠ΅ΡΡΠ²Π° Π·Π°Π±ΠΎΠ»Π΅Π²ΡΠΈΡ
COVID-19 ΠΈ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ Π³ΠΎΡΡΠ΄Π°ΡΡΡΠ²Π΅Π½Π½ΡΡ
ΠΌΠ΅Ρ; Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Ρ Π΄Π΅Π½Π΅ΠΆΠ½ΠΎ-ΠΊΡΠ΅Π΄ΠΈΡΠ½ΠΎΠΉ ΠΈ ΡΠΈΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊ ΠΏΡΠΈ Π²ΡΡ
ΠΎΠ΄Π΅ ΠΈΠ· ΠΊΡΠΈΠ·ΠΈΡΠ°; ΠΏΡΠΈΠΎΡΠΈΡΠ΅ΡΡ Π΄Π΅Π½Π΅ΠΆΠ½ΠΎ-ΠΊΡΠ΅Π΄ΠΈΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠΈ Π΄Π»Ρ Π²ΠΎΡΡΡΠ°Π½ΠΎΠ²Π»Π΅Π½ΠΈΡ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠΈ; ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ ΠΈ ΠΏΠ΅ΡΡΠΏΠ΅ΠΊΡΠΈΠ²Ρ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ ΠΌΠ΅Ρ Π΄Π΅Π½Π΅ΠΆΠ½ΠΎ-ΠΊΡΠ΅Π΄ΠΈΡΠ½ΠΎΠΉ ΠΈ ΡΠΈΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊ. Π‘Π΄Π΅Π»Π°Π½ Π²ΡΠ²ΠΎΠ΄, ΡΡΠΎ ΠΏΠΎΠΊΠ°Π·Π°ΡΠ΅Π»ΠΈ Π΄ΠΈΠ½Π°ΠΌΠΈΠΊΠΈ ΠΠΠ, Π±Π΅Π·ΡΠ°Π±ΠΎΡΠΈΡΡ, ΠΈΠ½ΡΠ»ΡΡΠΈΠΈ ΡΠ²Π»ΡΡΡΡΡ ΠΏΠΎΠ»Π΅Π·Π½ΡΠΌΠΈ ΠΎΡΠΈΠ΅Π½ΡΠΈΡΠ°ΠΌΠΈ Π΄Π»Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΠ΅ΠΊΡΡΠΈΡ
ΠΈ Π±ΡΠ΄ΡΡΠΈΡ
ΡΠΎΠ±ΡΡΠΈΠΉ Π² ΠΎΠ±Π»Π°ΡΡΠΈ Π΄Π΅Π½Π΅ΠΆΠ½ΡΡ
ΡΡΠ΅Π΄ΡΡΠ², ΠΊΡΠ΅Π΄ΠΈΡΠΎΠ² ΠΈ ΠΏΡΠΎΠΈΠ·Π²ΠΎΠ΄ΡΡΠ²Π°. Π ΡΠΎΠ²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
ΡΡΠ»ΠΎΠ²ΠΈΡΡ
ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½Π° Π½Π΅ΠΎΠ±Ρ
ΠΎΠ΄ΠΈΠΌΠΎΡΡΡ ΠΏΡΠΎΠ°ΠΊΡΠΈΠ²Π½ΡΡ
ΠΌΠ΅Ρ Π΄Π»Ρ Π±ΠΎΠ»Π΅Π΅ ΡΠ³Π»Π°ΠΆΠ΅Π½Π½ΠΎΠ³ΠΎ ΡΡΠ΅Π΄Π½Π΅Π³ΠΎ ΡΠΎΡΡΠ° ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊ. ΠΠ°ΠΆΠ΄Π°Ρ ΠΈΠ· Π΄Π²ΡΡ
ΠΎΠΏΠΈΡΠ°Π½Π½ΡΡ
(ΠΌΠΎΠ½Π΅ΡΠ°ΡΠ½ΠΎΠΉ ΠΈΠ»ΠΈ ΡΠΈΡΠΊΠ°Π»ΡΠ½ΠΎΠΉ) ΠΏΠΎΠ»ΠΈΡΠΈΠΊ ΠΈΠΌΠ΅Π΅Ρ ΡΠ²ΠΎΠΈ ΠΏΡΠ΅ΠΈΠΌΡΡΠ΅ΡΡΠ²Π° ΠΈ Π½Π΅Π΄ΠΎΡΡΠ°ΡΠΊΠΈ. Π ΡΠ°ΡΡΠ½ΠΎΡΡΠΈ, ΠΏΡΠΈ Π²ΡΠΏΠΎΠ»Π½Π΅Π½ΠΈΠΈ ΠΏΡΠΎΠ°ΠΊΡΠΈΠ²Π½ΡΡ
ΠΌΠ΅Ρ Π² ΠΌΠΎΠ½Π΅ΡΠ°ΡΠ½ΠΎΠΉ ΠΏΠΎΠ»ΠΈΡΠΈΠΊΠ΅ Π²ΡΠ΅Π³Π΄Π° Π½Π°Π±Π»ΡΠ΄Π°Π΅ΡΡΡ Π΄Π²Π° Π²ΡΠ΅ΠΌΠ΅Π½Π½ΡΡ
Π»Π°Π³Π°: Π² ΡΠ΅Π°ΠΊΡΠΈΠΈ Π½Π° ΡΠ΅ΡΠ΅ΡΡΠΈΡ ΠΈ Π²ΠΎ Π²ΡΠ΅ΠΌΠ΅Π½ΠΈ Π²Π»ΠΈΡΠ½ΠΈΡ ΠΏΡΠΈΠ½ΠΈΠΌΠ°Π΅ΠΌΡΡ
ΠΌΠ΅Ρ. ΠΠ»Ρ Π±ΠΎΡΡΠ±Ρ Ρ ΡΠ΅ΡΠ΅ΡΡΠΈΠ΅ΠΉ Π² ΡΠΊΠΎΠ½ΠΎΠΌΠΈΠΊΠ΅ ΠΏΡΠ°Π²ΠΈΡΠ΅Π»ΡΡΡΠ²Π°ΠΌ ΠΈ ΡΠ΅Π½ΡΡΠ°Π»ΡΠ½ΡΠΌ Π±Π°Π½ΠΊΠ°ΠΌ ΡΠ»Π΅Π΄ΡΠ΅Ρ Π±ΡΡΡ ΠΏΡΠΎΠ°ΠΊΡΠΈΠ²Π½ΡΠΌΠΈ, ΡΡΠΎ Π½Π°ΠΈΠ±ΠΎΠ»Π΅Π΅ Π²Π°ΠΆΠ½ΠΎ Π΄Π»Ρ Π½Π°ΡΠ΅Π»Π΅Π½ΠΈΡ
Microwave Absorption of Surface-State Electrons on Liquid He
We have investigated the intersubband transitions of surface state electrons
(SSE) on liquid He induced by microwave radiation at temperatures from 1.1
K down to 0.01 K. Above 0.4 K, the transition linewidth is proportional to the
density of He vapor atoms. This proportionality is explained well by Ando's
theory, in which the linewidth is determined by the electron - vapor atom
scattering. However, the linewidth is larger than the calculation by a factor
of 2.1. This discrepancy strongly suggests that the theory underestimates the
electron - vapor atom scattering rate. At lower temperatures, the absorption
spectrum splits into several peaks. The multiple peak structure is partly
attributed to the spatial inhomogeneity of the static holding electric field
perpendicular to the electron sheet.Comment: 15 pages, 7 figures, submitted to J. Phys. Soc. Jp
Microwave saturation of the Rydberg states of electrons on helium
We present measurements of the resonant microwave excitation of the Rydberg
energy levels of surface state electrons on superfluid helium. The temperature
dependent linewidth agrees well with theoretical predictions and is very small
below 300 mK. Absorption saturation and power broadening were observed as the
fraction of electrons in the first excited state was increased to 0.49, close
to the thermal excitation limit of 0.5. The Rabi frequency was determined as a
function of microwave power. The high values of the ratio of the Rabi frequency
to linewidth confirm this system as an excellent candidate for creating qubits.Comment: 4 pages, 4 figure
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