Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "74.70.Tx" wg kryterium: Temat


Wyświetlanie 1-10 z 10
Tytuł:
Point Contact Studies of High T$\text{}_{c}$ Superconductors
Autorzy:
Susła, B.
Meepagala, S. C.
Wolf, E. L.
Powiązania:
https://bibliotekanauki.pl/articles/1929570.pdf
Data publikacji:
1993-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.50.+r
74.70.Tx
Opis:
Point contact spectroscopy experiments were performed on both single crystals Bi$\text{}_{2}$Sr$\text{}_{2}$CaCu$\text{}_{2}$O$\text{}_{8+y}$ and BiSrCaCuO/Ag sintered material using gold tips. The spectra exhibit tunneling structure, which are interpreted in terms of the energy gap structure 2Δ = 58 meV at 4.2 K. We observed the strong Andreev reflection of the Au-BiSrCaCuO/Ag boundary.
Źródło:
Acta Physica Polonica A; 1993, 84, 2; 315-319
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Self-Induced Transparency in 1D Magnetics
Autorzy:
Borovick, A. E.
Borovikov, V. S.
Gorelik, L. Yu
Powiązania:
https://bibliotekanauki.pl/articles/1930595.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
75.30.Mb
74.70.Tx
Opis:
The evolution of spin system with the Fermi character of the relevant excitations under the strong magnetic field pulse is presented. The nonlinear dynamic equations describing interaction of the system and external magnetic field are found. It is shown that under certain conditions the initial state of the resonantly absorbing system does not change after passing of the field pulse (similar to optical self-induced transparency in two-level molecular gas).
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 405-407
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Non-Linear Processes in 1D Quantum Spin Ordered System under Strong Magnetic Field Pulse
Autorzy:
Borovikov, V. S.
Gorelik, L. Yu
Kulinich, S. I.
Popkov, V. Yu.
Powiązania:
https://bibliotekanauki.pl/articles/1963291.pdf
Data publikacji:
1997-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Tx
75.30.Mb
Opis:
Investigation of an exactly integrable quantum model of 1D magnetic (which is equivalent to a massive fermion system) is presented. It has been shown that under certain conditions a spin system will not absorb power from the strong homogeneous magnetic field pulse.
Źródło:
Acta Physica Polonica A; 1997, 91, 3; 605-608
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Fermion Superconductor Order Parameter in High Magnetic Field
Autorzy:
Kowalewski, L.
Wojciechowski, R.
Thomas, M.
Nogala, M.
Powiązania:
https://bibliotekanauki.pl/articles/1930573.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Tx
74.60.-w
74.90.+n
Opis:
It is shown that, independently on either the nature and the strength of pairing, the orbital effects of a high magnetic field in heavy fermion superconductor change the form of both the effective pairing and the gap function.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 347-350
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Superconductivity in Anderson Lattice Model
Autorzy:
Romano, A.
Noce, C.
Micnas, R.
Powiązania:
https://bibliotekanauki.pl/articles/1955827.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.72.-h
74.70.Tx
74.25.-q
Opis:
We study the superconducting instabilities generated by the inclusion in the Anderson lattice model of a density-density attractive potential between correlated electrons on nearest-neighbouring sites. Using a description of the normal phase based on a perturbative expansion around the atomic limit, we treat the attractive potential in the broken-symmetry Hartree-Fock scheme and analyze which of the possible symmetries of the superconducting order parameter leads to the highest possible transition temperature in the case of a two-dimensional square lattice. For values of the on-site f-repulsion large compared to the hopping amplitude, a suppression of any possible superconducting phase occurs, regardless of the symmetry of the order parameter.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 381-385
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Theory of Unconventional Superconductivity in Strongly Correlated Systems: Real Space Pairing and Statistically Consistent Mean-Field Theory - in Perspective
Autorzy:
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1431227.pdf
Data publikacji:
2012-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
74.70.Tx
74.20.-z
Opis:
In this brief overview we discuss the principal features of real space pairing as expressed via corresponding low-energy (t-J or periodic Anderson-Kondo) effective Hamiltonian, as well as consider concrete properties of those unconventional superconductors. We also rise the basic question of statistical consistency within the so-called renormalized mean-field theory. In particular, we provide the phase diagrams encompassing the stable magnetic and superconducting states. We interpret real space pairing as correlated motion of fermion pair coupled by short-range exchange interaction of magnitude J comparable to the particle renormalized band energy ≈ tx, where x is the carrier number per site. We also discuss briefly the difference between the real-space and the paramagnon-mediated sources of superconductivity. The paper concentrates both on recent novel results obtained in our research group, as well as puts the theoretical concepts in a conceptual as well as historical perspective. No slave-bosons are required to formulate the present approach.
Źródło:
Acta Physica Polonica A; 2012, 121, 4; 764-784
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Magnetic Impurities in Gapless Fermi Systems
Autorzy:
Borkowski, L. S.
Powiązania:
https://bibliotekanauki.pl/articles/1955519.pdf
Data publikacji:
1997-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.15.Qm
75.20.Hr
74.70.Tx
Opis:
In ordinary metals, antiferromagnetic exchange between conduction electrons and a magnetic impurity leads to screening of the impurity spin below the Kondo temperature, T$\text{}_{K}$. In systems such as semimetals, small-gap semiconductors and unconventional superconductors, a reduction in available conduction states near the chemical potential can greatly depress T$\text{}_{K}$. The behavior of an Anderson impurity in a model with a power-law density of states, ρ(ε) ∝ |ε|$\text{}^{r}$, r>0, for |ε|<Δp, where Δp is small compared to the bandwidth, is studied using the non-crossing approximation. The transition from the Kondo singlet to the magnetic ground state can be seen in the behavior of the impurity magnetic susceptibility χ. The product Tχ saturates at a finite value at low temperature for coupling smaller than the critical one. For sufficiently large coupling Tχ → 0, as T → 0, indicating a complete screening of the impurity spin.
Źródło:
Acta Physica Polonica A; 1997, 91, 2; 359-362
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anomalous Superconductivity and Antiferromagnetism in the U(Pt,Pd)$\text{}_{3}$ System
Autorzy:
Franse, J. J. M.
Powiązania:
https://bibliotekanauki.pl/articles/2030394.pdf
Data publikacji:
2001-12
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.27.+a
74.70.Tx
75.30.Mb
Opis:
A review is presented of the anomalous magnetic and superconducting properties of the heavy-fermion compound UPt$\text{}_{3}$ that has been a subject of extensive study during the past twenty years. The normal-state and superconducting properties of the compound were evaluated from magnetic, transport, and thermodynamic studies. In addition, neutron-diff raction and muon spin relaxation experiments were performed in the normal and superconducting states. The compound is characterized by a multiple superconducting phase diagram and by the coexistence of superconductivity and short-range antiferromagnetic interactions with quasi-static moments of the order of 10$\text{}^{-2}$μ$\text{}_{B}$/U-atom. Upon substituting Pt by Pd, the short-range magnetic interactions give way to long-range antiferromagnetic order with a maximal ordering temperature of 6 K for the 5 at.% Pd alloy and a magnetic moment of 0.6μ$\text{}_{B}$/U-atom. Superconductivity and long-range antiferromagnetic order are in competition resulting in a critical composition of 0.6 at.% Pd. At this concentration, non-Fermi liquid behaviour is observed.
Źródło:
Acta Physica Polonica A; 2001, 100, Supplement; 153-176
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Magnetism in $UCo_{0.88}Ru_{0.12}Ge$ Studied by Polarized Neutrons
Autorzy:
Vališka, M.
Pospíšil, J.
Nénert, G.
Stunault, A.
Prokeš, K.
Sechovský, V.
Powiązania:
https://bibliotekanauki.pl/articles/1371426.pdf
Data publikacji:
2014-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Tx
61.05.fm
75.25.-j
Opis:
UCoGe is an archetype of coexisting weak itinerant 5f-electron ferromagnetism ($T_{C}$~3 K, $μ_{s}$=$0.03μ_{B}$/f.u.) and superconductivity ($T_{SC}$~ 0.6 K) at ambient pressure. The Ru substitution for Co leads to an initial sharp increase of the $T_{C}$ up to the maximum of $T_{C}$=8.5 K for x=0.12, increase of spontaneous magnetic moment and suppression of superconductivity. We have grown the $UCo_{0.88}Ru_{0.12}Ge$ single crystal and studied magnetization along the principal crystallographic axes. To see the microscopic background of these findings we performed a polarized neutron diffraction experiment on D3 diffractometer in ILL. We have found that the Co and U moments are parallel in $UCo_{0.88}Ru_{0.12}Ge$, in contrast to the antiparallel configuration in UCoGe. This is probably the reason of the spontaneous magnetization increase with Ru doping.
Źródło:
Acta Physica Polonica A; 2014, 126, 1; 330-331
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Universal Scaling of Basic Properties of the Heavy-Fermion Superconductors
Autorzy:
Karbowski, J.
Spałek, J.
Powiązania:
https://bibliotekanauki.pl/articles/1930572.pdf
Data publikacji:
1994-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
74.70.Tx
75.30.Mb
71.28.+d
Opis:
We show that the properties of the heavy-electron superconducting state induced by the interorbital kinetic exchange scale with the effective mass renormalization m*/m$\text{}_{0}$ ~ 1/T$\text{}_{K}$. Explicitly, the pairing potential J̃ ~ J(m$\text{}_{0}$/m*)ln$\text{}^{2}$(m$\text{}_{0}$/m*), where J is the magnitude of the bare Kondo coupling; the coherence length ξ ~ T$\text{}_{K}$/T$\text{}_{c}$ where T$\text{}_{c}$ is the transition temperature, whereas the penetration depth λ ~ (m*/m$\text{}_{0}$)$\text{}^{½}$ so that λ/ξ >> 1. We also determine the scaling of magnetic critical fields.
Źródło:
Acta Physica Polonica A; 1994, 85, 2; 341-345
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-10 z 10

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies