Perturbative approach to tunneling and quantum interferences in spin clusters
Graph Chatbot
Chattez avec Graph Search
Posez n’importe quelle question sur les cours, conférences, exercices, recherches, actualités, etc. de l’EPFL ou essayez les exemples de questions ci-dessous.
AVERTISSEMENT : Le chatbot Graph n'est pas programmé pour fournir des réponses explicites ou catégoriques à vos questions. Il transforme plutôt vos questions en demandes API qui sont distribuées aux différents services informatiques officiellement administrés par l'EPFL. Son but est uniquement de collecter et de recommander des références pertinentes à des contenus que vous pouvez explorer pour vous aider à répondre à vos questions.
In this thesis, the magnetic properties of self-assembled 3d and 4d metal nano-structures supported on surfaces have been investigated. The atomic coordination within the nano-structures was found to profoundly affect important quantities such as the magne ...
We present a precise equivalence of the Lifson-Poland-Scheraga model with wetting models. Making use of a representation of the former model in terms of random matrices, we obtain, in the limit of weak disorder, a mean-field approximation, that shows a cha ...
This work addresses the problem of reducing the time between query submission and results output in a retrieval system. The goal is achieved by considering only a database fraction as small as possible during the retrieval process. Our approach is based on ...
The study of \emph{quantum magnetism} remains at the forefront of condensed matter physics. Spin models provide a large class of many-body systems, in which cooperative quantum phenomena can be studied in a controlled way. In addition, the \emph{neutron sc ...
The ground state and zero-temperature magnetization process of the spin-1/2 Ising-Heisenberg model on two-dimensional triangles-in-triangles lattices are exactly calculated using eigenstates of the smallest commuting spin clusters. Our ground-state analysi ...
Motivated by the recent discovery of a spin-liquid phase for the Hubbard model on the honeycomb lattice at half-filling (Meng et al 2010 Nature 88 487), we apply both perturbative and non-perturbative techniques to derive effective spin Hamiltonians descri ...
We study the T=0 magnetization of frustrated two-leg spin ladders with arbitrary value of the spin S. In the strong-rung limit, we use degenerate perturbation theory to prove that frustration leads to magnetization plateaus at fractional values of the magn ...
The spin-1/2 Ising-Heisenberg model on two geometrically related triangles-in-triangles lattices is exactly solved through the generalized star-triangle transformation, which establishes a rigorous mapping correspondence with the effective spin-1/2 Ising m ...