Temat: 05.45.+b - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Asymmetry Induced Localization
Autorzy:: Kohler, H.
Powiązania:: https://bibliotekanauki.pl/articles/1399044.pdf
Data publikacji:: 2013-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.30.-d
03.65.Yz
05.45.Mt
73.23.-b
Opis:: We consider a two-level system, which couples via non-commuting operators to two independent oscillator baths. When the coupling is symmetric, the renormalized hopping matrix element is finite even for infinitely strong coupling strength. The two-level system is in a delocalized phase. For finite coupling strength a localization transition occurs for a critical asymmetry angle, which separates the localized from the delocalized phase. Using the method of flow equations we are able to monitor real time dynamics.
Źródło:: Acta Physica Polonica A; 2013, 124, 6; 1053-1059
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Fidelity Decay in Chaotical and Random Systems
Autorzy:: Kohler, H.
Powiązania:: https://bibliotekanauki.pl/articles/1492437.pdf
Data publikacji:: 2011-12
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 05.30.-d
03.65.Yz
05.45.Mt
73.23.-b
Opis:: Fidelity is the overlap of wave functions with the same initial state propagated in time by slightly different Hamiltonians. Its behavior depends crucially on the choice of the initial wave function state. We review two cases: first, the initial state is random. In this case a simple analytic relation with parametric spectral correlations can be established. The latter quantity is completely determined by the spectral data and can therefore be measured, without knowledge about the wave function. Second, the initial state is an eigenstate of the unperturbed system. In this case fidelity is identical to the survival probability. We find unexpected features like revival and non-ergodicity. In this case fluctuations around the mean are large and the full fidelity distribution becomes a non-trivial function. The full fidelity distribution can be calculated in the long time limit and for small perturbations.
Źródło:: Acta Physica Polonica A; 2011, 120, 6A; A-119-A-126
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Statistics of Conductance and Shot-Noise Power for Chaotic Cavities
Autorzy:: Sommers, H.-J.
Wieczorek, W.
Savin, D. V.
Powiązania:: https://bibliotekanauki.pl/articles/2047832.pdf
Data publikacji:: 2007-10
Wydawca:: Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:: 73.23.-b
73.50.Td
05.45.Mt
73.63.Kv
Opis:: We report on an analytical study of the statistics of conductance, g, and shot-noise power, p, for a chaotic cavity with arbitrary numbers N$\text{}_{1,2}$ of channels in two leads and symmetry parameterβ = 1, 2, 4. With the theory of Selberg's integral the first four cumulants of g and first two cumulants of p are calculated explicitly. We give analytical expressions for the conductance and shot-noise distributions and determine their exact asymptotics near the edges up to linear order in distances from the edges. For 0 < g < 1 a power law for the conductance distribution is exact. All results are also consistent with numerical simulations.
Źródło:: Acta Physica Polonica A; 2007, 112, 4; 691-697
0587-4246
1898-794X
Pojawia się w:: Acta Physica Polonica A
Dostawca treści:: Biblioteka Nauki

Artykuł

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