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S. N. Burmistrov

Publications and source records attributed to S. N. Burmistrov.

16 recordsLinked to original sources
arXiv2023

Ginzburg-Landau approximation for the Hubbard model in the external magnetic field

The Hubbard model is studied in the external magnetic field. The analysis is carried out phenomenologically within the framework of the Ginzburg-Landau theory with the order parameter describing the opposite spin electrons. The study is performed for the nearly half-filled lower Hubbard band in the metallic state. The final equations are the Pauli-like ones for the opposite spins and nonlinear as a result of interaction between electrons with the opposite spins. The equations can analytically be solved for the spatially homogeneous distributions in a number of most interesting cases. In particular, the problem on the metal-insulator transition is analyzed for the nearly half-filled Hubbard sub-bands. The critical magnetic field at which the transition from the metallic state to the insulator one takes place is found under the paramagnetic spin effect.

cond-mat.str-el↗
arXiv2022

Cavitation on single electron bubbles in liquid helium at small negative pressure

Liquid helium under negative pressure represents a unique possibility for studying the macroscopic quantum nucleation phenomena in condensed media. We analyze the quantum cavitation rate of single electron bubbles at low temperatures down to absolute zero. The energy dissipation and sound emission processes result in the different temperature behavior of quantum cavitation rate in normal fluid $^3$He and superfluid $^4$He below the thermal-quantum crossover temperature. The position of rapid nucleation line in the temperature-pressure phase diagram is discussed as well.

cond-mat.other↗
arXiv2021

Quantum nucleation of gas bubbles in liquid helium

Liquid helium under negative pressures represents a unique possibility for studying nucleation and growth dynamics of cavities at low temperatures down to absolute zero. We analyze the growth dynamics of cavities and determine the temperature behavior of quantum cavitation rate and the crossover temperature between the classical and quantum cavitation mechanisms. The energy dissipation processes, which differ in kind in normal fluid $^3$He and superfluid $^4$He, result in the different temperature behavior of cavitation rate in $^3$He and $^4$He below the thermal-quantum crossover temperature.

cond-mat.other↗
arXiv2019

On the transmission of crystallisation waves across the edge between the rough and faceted crystalline surfaces in superfluid 4He

The wavelike processes of crystallisation and melting or crystallisation waves are well-known to exist at the crystal 4He surface in its rough state. Below the roughening transition temperature the crystal surface experiences the transition to the smooth faceted state and the crystallisation waves represent the propagation of a train of crystalline steps at the velocity depending on the crystal step height. Here we analyse the transmission and reflection of crystallisation waves propagating across the crystal edge separating the crystal surface in the rough and faceted states.

cond-mat.other↗
arXiv2018

Nucleation at quantized vortices and the heterogeneous phase separation in supersaturated superfluid 3He-4He liquid mixtures

Supersaturated superfluid 3He-4He liquid mixture, separating into the 3He-concentrated c-phase and 3He-diluted d-phase, represents a unique possibility for studying macroscopic quantum nucleation and quantum phase-separation kinetics in binary mixtures at low temperatures down to absolute zero. One of possible heterogeneous mechanisms for the phase separation of supersaturated d-phase is associated with superfluidity of this phase and with a possible existence of quantized vortices playing a role of nucleation sites for the c-phase of liquid mixture. We analyze the growth dynamics of vortex core filled with the c-phase and determine the temperature behavior of c-phase nucleation rate and the crossover temperature between the classical and quantum nucleation mechanisms.

cond-mat.other↗
arXiv2016

On the Lifetime of Metastable Metallic Hydrogen

The molecular phase of hydrogen converts to the atomic metallic phase at high pressures estimated usually as 300 - 500 GPa. We analyze the decay of metallic phase as the pressure is relieved below the transition one. The metallic state is expected to be in the metastable long-lived state down to about 10 - 20 GPa and decays instantly at the lower pressures. The pressure range of the long-lived metastable state is directly associated with an impossibility to produce a stable hydrogen molecule immersed into the electron liquid of high density. For lower pressures, the nucleation of an electron-free cavity with the energetically favorable hydrogen molecule inside cannot be suppressed with the low ambient pressure.

cond-mat.other↗
arXiv2012

Charge-induced instability and macroscopic quantum nucleation phenomena at the crystal 4He facet

An existence of the charge-induced instability is well known for the 4He crystal surface in the rough state. Much less is known about charge-induced instability at the 4He crystal surface in the smooth well-faceted state below the roughening transition temperature. To meet the lack, we examine here the latter case. As long as the electric field normal to the crystal facet is below the critical value same as for the rough surface, the crystal faceting remains absolutely stable. Above the critical field, unlike absolutely unstable state of the rough surface, the crystal facet crosses over to the metastable state separated from new crushed state with a potential barrier proportional to the square of the linear facet step energy. The onset and development of the instability at the charged crystal facet has much in common with the nucleation kinetics of first-order phase transitions. Depending on the temperature, the electric breaking strength is determined either by thermal activation at high temperatures or by quantum tunneling at sufficiently low temperatures.

cond-mat.other↗
arXiv2011

Dissipative dynamics of the Josephson effect in the binary Bose-condensed mixtures

The dissipative dynamics of a pointlike Josephson junction in binary Bose-condensed mixtures is analyzed within the framework of the model of a tunneling Hamiltonian. The transmission of unlike particles across a junction is described by the different transmission amplitudes. The effective action that describes the dynamics of the phase differences across the junction for each of two condensed components is derived employing the functional integration method. In the low-frequency limit the dynamics of a Josephson junction can be described by two coupled equations in terms of the potential energy and dissipative Rayleigh function using a mechanical analogy. The interplay between mass currents of each mixture component appears in the second-order term in the tunneling amplitudes due to interspecies hybridizing interaction. The asymmetric case of the binary mixtures with the different concentration and order parameters is considered as well.

cond-mat.quant-gas↗
arXiv2011

Instability of a crystal 4He facet in the field of gravity

We analyze the analog of the Rayleigh instability in the field of gravity for the superfluid-crystal 4He interface provided that the heavier 4He crystal phase occupies the half-space over the lighter superfluid phase. The conditions and the onset of the gravitational instability are different in kind above and below the roughening transition temperature when the crystal 4He surface is in the rough or in the smooth faceted state, respectively. In the rough state of the surface the gravitational instability is similar to the classical case of the fluid-fluid interface. In contrast, in the case of the crystal faceted surface the onset of the gravitational instability is associated with surmounting some potential barrier. The potential barrier results from nonzero magnitude of the linear facet step energy. The size and the tilting angle of the crystal facet are also important parameters for developing the instability. The initial stage of the instability can be described as a generation of crystallization waves at the superfluid-crystal interface. The experiments which may concern the gravitational instability of the superfluid-crystal 4He interface are discussed.

cond-mat.other↗
arXiv2010

On the spectrum of facet crystallization waves at the smooth 4He crystal surface

The wavelike processes of crystallization and melting or crystallization waves are well known to exist at the 4He crystal surface in the rough state. Much less is known about crystallization waves for the 4He crystal surface in the smooth well-faceted state below the roughening transition temperature. To meet the lack, we analyze here the spectrum of facet crystallization waves and its dependence upon the wavelength, perturbation amplitude, and the number of possible facet steps distributed somehow over the wavelength. All the distinctive features of facet crystallization waves from conventional waves at the rough surface result from a nonanalytic cusplike behavior in the angle dependence for the surface tension of smooth crystal facets.

cond-mat.other↗
arXiv2010

Rayleigh-Taylor instability of crystallization waves at the superfluid-solid 4He interface

At the superfluid-solid 4He interface there exist crystallization waves having much in common with gravitational-capillary waves at the interface between two normal fluids. The Rayleigh-Taylor instability is an instability of the interface which can be realized when the lighter fluid is propelling the heavier one. We investigate here the analogues of the Rayleigh-Taylor instability for the superfluid-solid 4He interface. In the case of a uniformly accelerated interface the instability occurs only for a growing solid phase when the magnitude of the acceleration exceeds some critical value independent of the surface stiffness. For the Richtmyer-Meshkov limiting case of an impulsively accelerated interface, the onset of instability does not depend on the sign of the interface acceleration. In both cases the effect of crystallization wave damping is to reduce the perturbation growth-rate of the Taylor unstable interface.

cond-mat.other↗
arXiv2008

Hydrodynamic instability during non-uniform growth of a helium crystal

We analyze an analog of the hydrodynamic Rayleigh-Taylor instability for the liquid-solid phase interface under non-uniform growth of the solid phase. The development of the instability starts on conditions of an accelerated interface growth and if the magnitude of acceleration exceeds some critical value. The plane and spherical shapes of the interface are considered. The observation of the instability can be expected for helium crystals in the course of their abnormal fast growth.

cond-mat.other↗
arXiv2004

Underbarrier nucleation kinetics in a metastable quantum liquid near the spinodal

We develop a theory in order to describe the effect of relaxation in a condensed medium upon the quantum decay of a metastable liquid near the spinodal at low temperatures. We find that both the regime and the rate of quantum nucleation strongly depend on the relaxation time and its temperature behavior. The quantum nucleation rate slows down with the decrease of the relaxation time. We also discuss the low temperature experiments on cavitation in normal $^3$He and superfluid $^4$He at negative pressures. It is the sharp distinctions in the high frequency sound mode and in the temperature behavior of the relaxation time that make the quantum cavitation kinetics in $^3$He and $^4$He completely different in kind.

cond-mat.stat-mech↗
arXiv2003

Dissipative Dynamics of a Josephson Junction In the Bose-Gases

The dissipative dynamics of a Josephson junction in the Bose-gases is considered within the framework of the model of a tunneling Hamiltonian. The effective action which describes the dynamics of the phase difference across the junction is derived using functional integration method. The dynamic equation obtained for the phase difference across the junction is analyzed for the finite temperatures in the low frequency limit involving the radiation terms. The asymmetric case of the Bose-gases with the different order parameters is calculated as well.

cond-mat.soft↗
arXiv2001

Vibrational and acoustical properties of a liquid drop in the phase-separated fluid with a highly mobile interface

We study the oscillation spectrum and acoustic properties of a liquid drop in the phase-separated fluid when the interfacial dynamics of phase conversion can be described in terms of the kinetic growth coefficient. For a readily mobile interface, i.e., as the growth coefficient becomes comparable with a reciprocal of the acoustic impedance, anomalous behavior is found in the oscillation spectrum of a drop as well as in the velocity and absorption of a sound wave propagating through a suspension of drops in the two-phase system. Compared with the known case of two immiscible fluids, the high interface mobility leads to an anomalous softening of the radial drop pulsations and to the frequency- and temperature-dependent behavior for the sound velocity and absorption coefficient in a two-phase suspension.

cond-mat.soft↗