FRINK Linked Data Fragments server

Matches in SemOpenAlex for { <https://semopenalex.org/work/W2189446543> ?p ?o ?g. }

• W2189446543 abstract "This thesis aims at a description of the equilibrium dynamics of quantum spin glass systems. To this end a generic fermionic SU(2), spin 1/2 spin glass model with infinite-range interactions is defined in the first part. The model is treated in the framework of imaginary-time Grassmann field theory along with the replica formalism. A dynamical two-step decoupling procedure, which retains the full time dependence of the (replica-symmetric) saddle point, is presented. As a main result, a set of highly coupled self-consistency equations for the spin-spin correlations can be formulated. Beyond the so-called spin-static approximation two complementary systematic approximation schemes are developed in order to render the occurring integration problem feasible. One of these methods restricts the quantum-spin dynamics to a manageable number of bosonic Matsubara frequencies. A sequence of improved approximants to some quantity can be obtained by gradually extending the set of employed discrete frequencies. Extrapolation of such a sequence yields an estimate of the full dynamical solution. The other method is based on a perturbative expansion of the self-consistency equations in terms of the dynamical correlations. In the second part these techniques are applied to the isotropic Heisenberg spin glass both on the Fock space (HSGF) and, exploiting the Popov-Fedotov trick, on the spin space (HSGS). The critical temperatures of the paramagnet to spin glass phase transitions are determined accurately. Compared to the spin-static results, the dynamics causes slight increases of T_c by about 3% and 2%, respectively. For the HSGS the specific heat C(T) is investigated in the paramagnetic phase and, by way of a perturbative method, below but close to T_c. The exact C(T)-curve is shown to exhibit a pronounced non-analyticity at T_c and, contradictory to recent reports by other authors, there is no indication of maximum above T_c. In the last part of this thesis the spin glass model is augmented with a nearest-neighbor hopping term on an infinite-dimensional cubic lattice. An extended self-consistency structure can be derived by combining the decoupling procedure with the dynamical CPA method. For the itinerant Ising spin glass numerous solutions within the spin-static approximation are presented both at finite and zero temperature. Systematic dynamical corrections to the spin-static phase diagram in the plane of temperature and hopping strength are calculated, and the location of the quantum critical point is determined." @default.
• W2189446543 created "2016-06-24" @default.
• W2189446543 creator A5024096311 @default.
• W2189446543 date "2004-01-01" @default.
• W2189446543 modified "2023-10-16" @default.
• W2189446543 title "Dynamics in Quantum Spin Glass Systems" @default.
• W2189446543 cites W1486949085 @default.
• W2189446543 cites W1488001281 @default.
• W2189446543 cites W1527520754 @default.
• W2189446543 cites W1534065249 @default.
• W2189446543 cites W1566049037 @default.
• W2189446543 cites W1654315441 @default.
• W2189446543 cites W1705200387 @default.
• W2189446543 cites W1965394077 @default.
• W2189446543 cites W1968548964 @default.
• W2189446543 cites W1971565000 @default.
• W2189446543 cites W1972258867 @default.
• W2189446543 cites W1973177836 @default.
• W2189446543 cites W1975247443 @default.
• W2189446543 cites W1977292929 @default.
• W2189446543 cites W1984895795 @default.
• W2189446543 cites W1985707471 @default.
• W2189446543 cites W1988150410 @default.
• W2189446543 cites W1991484859 @default.
• W2189446543 cites W1996270455 @default.
• W2189446543 cites W1999149566 @default.
• W2189446543 cites W2000449275 @default.
• W2189446543 cites W2007833526 @default.
• W2189446543 cites W2008348370 @default.
• W2189446543 cites W2011280309 @default.
• W2189446543 cites W2017489794 @default.
• W2189446543 cites W2022494241 @default.
• W2189446543 cites W2022820481 @default.
• W2189446543 cites W2024275627 @default.
• W2189446543 cites W2031839553 @default.
• W2189446543 cites W2034398686 @default.
• W2189446543 cites W2034783791 @default.
• W2189446543 cites W2036384574 @default.
• W2189446543 cites W2036876475 @default.
• W2189446543 cites W2037495924 @default.
• W2189446543 cites W2040088637 @default.
• W2189446543 cites W2050245998 @default.
• W2189446543 cites W2056164197 @default.
• W2189446543 cites W2056276949 @default.
• W2189446543 cites W2059071390 @default.
• W2189446543 cites W2061325384 @default.
• W2189446543 cites W2061362732 @default.
• W2189446543 cites W2062209307 @default.
• W2189446543 cites W2071421800 @default.
• W2189446543 cites W2074919599 @default.
• W2189446543 cites W2087201577 @default.
• W2189446543 cites W2107700858 @default.
• W2189446543 cites W2133671888 @default.
• W2189446543 cites W2997872173 @default.
• W2189446543 cites W3004253659 @default.
• W2189446543 cites W3212613575 @default.
• W2189446543 cites W574971530 @default.
• W2189446543 cites W3039674623 @default.
• W2189446543 hasPublicationYear "2004" @default.
• W2189446543 type Work @default.
• W2189446543 sameAs 2189446543 @default.
• W2189446543 citedByCount "0" @default.
• W2189446543 crossrefType "journal-article" @default.
• W2189446543 hasAuthorship W2189446543A5024096311 @default.
• W2189446543 hasConcept C114852677 @default.
• W2189446543 hasConcept C121332964 @default.
• W2189446543 hasConcept C121864883 @default.
• W2189446543 hasConcept C132459708 @default.
• W2189446543 hasConcept C134306372 @default.
• W2189446543 hasConcept C142362112 @default.
• W2189446543 hasConcept C150775274 @default.
• W2189446543 hasConcept C153349607 @default.
• W2189446543 hasConcept C2775937380 @default.
• W2189446543 hasConcept C33923547 @default.
• W2189446543 hasConcept C42704618 @default.
• W2189446543 hasConcept C62520636 @default.
• W2189446543 hasConcept C84114770 @default.
• W2189446543 hasConcept C97355855 @default.
• W2189446543 hasConceptScore W2189446543C114852677 @default.
• W2189446543 hasConceptScore W2189446543C121332964 @default.
• W2189446543 hasConceptScore W2189446543C121864883 @default.
• W2189446543 hasConceptScore W2189446543C132459708 @default.
• W2189446543 hasConceptScore W2189446543C134306372 @default.
• W2189446543 hasConceptScore W2189446543C142362112 @default.
• W2189446543 hasConceptScore W2189446543C150775274 @default.
• W2189446543 hasConceptScore W2189446543C153349607 @default.
• W2189446543 hasConceptScore W2189446543C2775937380 @default.
• W2189446543 hasConceptScore W2189446543C33923547 @default.
• W2189446543 hasConceptScore W2189446543C42704618 @default.
• W2189446543 hasConceptScore W2189446543C62520636 @default.
• W2189446543 hasConceptScore W2189446543C84114770 @default.
• W2189446543 hasConceptScore W2189446543C97355855 @default.
• W2189446543 hasLocation W21894465431 @default.
• W2189446543 hasOpenAccess W2189446543 @default.
• W2189446543 hasPrimaryLocation W21894465431 @default.
• W2189446543 hasRelatedWork W126552317 @default.
• W2189446543 hasRelatedWork W1814915480 @default.
• W2189446543 hasRelatedWork W1971560036 @default.
• W2189446543 hasRelatedWork W1978710047 @default.
• W2189446543 hasRelatedWork W1994630625 @default.

• next