排序方式: 共有59条查询结果,搜索用时 15 毫秒
51.
The stability of a fermion system is analyzed for a model repulsive pair interaction potential. The possibility of different
types of restructuring of the Fermi ground state (at sufficiently great coupling constant) is related to the analyticity properties
of such potential. In particular, for the screened Coulomb law it is shown that the restructuring cannot be of the Fermi condensation
type, known earlier for some exactly solvable models, but instead belongs to the class of topological transitions. A phase
diagram constructed for this model in the variables “screening parameter-coupling constant” displays two kinds of topological
transitions: a “5/2” kind, similar to the known Lifshitz transitions in metals, and a “2” kind, characteristic for a uniform
strongly interacting system.
Pis'ma Zh. éksp. Teor. Fiz. 68, No. 12, 893–899 (25 December 1998)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
52.
The specific features of fermion condensation — a phase transition associated with the rearrangement of the one-particle degrees
of freedom in strongly correlated Fermi systems — by which this phenomenon can be detected experimentally are discussed.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 11, 828–833 (10 June 1997) 相似文献
53.
J. Dukelsky V.A. Khodel P. Schuck V.R. Shaginyan 《Zeitschrift für Physik B Condensed Matter》1997,102(2):245-254
The phenomenon of the so called Fermion condensation, a phase transition analogous to Bose condensation but for Fermions, postulated in the past to occur in systems with strong momentum dependent forces, is reanalyzed in a model with infinite range interactions. The strongly non Fermi Liquid behavior of this system is demonstrated analytically at T = 0 and at T ≠ 0 in the superconducting and normal phases. The validity of the quasiparticle picture is investigated and seen to hold true for temperatures less than the characteristic temperature T f of the Fermion condensation. 相似文献
54.
55.
An infinite system of neutrons interacting by a model pair potential is considered. We investigate a case when this potential
is sufficiently strong attractive, so that its scattering length a tends to infinity, a
. It appeared, that if the structure of the potential is simple enough, including no finite parameters, reliable evidences
can be presented that such a system is completely unstable at any finite density. The incompressibility as a function of the
density is negative, reaching zero value when the density tends to zero. If the potential contains a sufficiently strong repulsive
core then the system possesses an equilibrium density. The main features of a theory describing such systems are considered.
Received: 17 December 1999 / Accepted: 23 December 1999 相似文献
56.
A rise in the condensation surface temperature during film growth is a result of energy dissipation on the condensation surface. An example of energy dissipation is the dissipation of chemical reaction heat, which releases during film deposition by reactive magnetron sputtering. The monitoring of the surface temperature during TiN film deposition by reactive (Ti–in–N2) and nonreactive (TiN–in–Ar or TiN–in–N2) sputtering methods has shown that this temperature is higher in the reactive case and decreases in the (TiN–in–Ar)–(TiN–in–N2) sequence of nonreactive sputtering modifications. It has been found that the composition and crystal structure of TiN films do not depend on the growth method and are identical to those of bulk titanium nitride. Based on these results, a formation mechanism of films obtained by the above methods has been suggested. In the case of reactive sputtering, the film was supposed to grow on the condensation surface through a reaction between titanium and nitrogen atoms. In the cases of nonreactive sputtering, the film forms from TiN molecules. 相似文献
57.
Using the theory of high-temperature superconductivity based on the idea of the fermion-condensation quantum phase transition (FCQPT), we show that neither the d-wave pairing symmetry, the pseudogap phenomenon, nor the presence of the Cu-O2 planes is of decisive importance for the existence of high-T c superconductivity. We analyze recent experimental data on this type of superconductivity in different materials and show that these facts can be understood within the theory of superconductivity based on the FCQPT. The latter can be considered as a universal cause of high-T c superconductivity. The main features of a room-temperature superconductor are discussed. 相似文献
58.
It is shown that the phase transition of density-wave origin in homogeneous liquids is preceded by fermion condensation. Thus
fermion condensation may be observed in low-density electron liquids, neutron stars, and liquid He3. Three-dimensional (3D) and two-dimensional (2D) liquids are considered.
Pis’ma Zh. éksp. Teor. Fiz. 65, No. 3, 242–247 (10 February 1997)
Published in English in the original Russian journal. Edited by Steve Torstveit. 相似文献
59.
We analyze measurements of the magnetization, differential susceptibility and specific heat of quasi-onedimensional insulator Cu(C4H4N2)(NO3)2 (CuPzN) subjected to magnetic fields. We show that the thermodynamic properties are defined by quantum spin liquid formed with spinons, with the magnetic field tuning the insulator CuPzN towards quantum critical point related to fermion condensation quantum phase transition (FCQPT) at which the spinon effective mass diverges kinematically. We show that the FCQPT concept permits to reveal and explain the scaling behavior of thermodynamic characteristics. For the first time, we construct the schematic T–H (temperature-magnetic field) phase diagram of CuPzN that contains Landau–Fermi-liquid, crossover and non-Fermi liquid parts, thus resembling that of heavy-fermion compounds. 相似文献