Zobrazeno 1 - 10
of 73
pro vyhledávání: '"Vítor R. Vieira"'
We analyze the thermodynamical limit of the quantum metric along critical submanifolds of theory space. Building upon various results previously known in the literature, we relate its singular behavior to normal directions, which are naturally associ
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::fbff2a105f10f031c35c15e4e3c4c059
http://arxiv.org/abs/2201.01329
http://arxiv.org/abs/2201.01329
Publikováno v:
Journal of physics. Condensed matter : an Institute of Physics journal. 31(48)
The Uhlmann connection is a mixed state generalisation of the Berry connection. The latter has a very important role in the study of topological phases at zero temperature. Closely related, the quantum fidelity is an information theoretical quantity
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::9c9a0b850efdb5ca8ea31c3c22b3c878
https://pubmed.ncbi.nlm.nih.gov/31426047
https://pubmed.ncbi.nlm.nih.gov/31426047
We study the behaviour of the fidelity and the Uhlmann connection in two-dimensional systems of free fermions that exhibit non-trivial topological behavior. In particular, we use the fidelity and a quantity closely related to the Uhlmann factor in or
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::c1075061d6c65694a112a789b6ae5d09
We study the behaviour of the Uhlmann connection in systems of fermions undergoing phase transitions. In particular, we analyse some of the paradigmatic cases of topological insulators and superconductors in dimension one, as well as the BCS theory o
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a3b55027d78ab5bde54a7de7e85eb902
http://arxiv.org/abs/1702.07289
http://arxiv.org/abs/1702.07289
Publikováno v:
Physica E: Low-dimensional Systems and Nanostructures. 51:29-36
Cylindrical and prismatic nano-structures (nano-wires and pores) with circular and hexagonal cross-section are studied using mirror boundary conditions to solve the Schrodinger equation in effective mass approximation. In comparison with “quantum b
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::38102805455c5ea5cab78abba86966e1
https://doi.org/10.1016/j.physe.2013.02.005
https://doi.org/10.1016/j.physe.2013.02.005
Autor:
Pedro D. Sacramento, Vítor R. Vieira
Mappings between models may be obtained by unitary transformations with preservation of the spectra but in general a change in the states. Non- canonical transformations in general also change the statistics of the operators involved. In these cases
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::b8ea314d67b979434ee166c50eb401f3
We perform the fidelity analysis for Boltzmann-Gibbs-like states in order to investigate whether the topological order of 1D fermionic systems at zero temperature is maintained at finite temperatures. We use quantum walk protocols that are known to s
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a3f3ffddd75694bf9d6f48dc397f47a5
Autor:
Yuri V. Vorobiev, Luis Gerardo Trápaga-Martínez, Pedro Ribeiro, Paul P. Horley, Vítor R. Vieira, Jesús González-Hernández
Publikováno v:
Physica E: Low-dimensional Systems and Nanostructures. 44:1602-1607
This paper is focused on analytical solution of the quantum–mechanical problem describing a particle confined into a pyramid-shaped quantum well. This type of micro- and nano-scale objects can be formed on the surface of semiconductor material as t
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::2f41e1a33a636da9ff4aae59f50ba38c
https://doi.org/10.1016/j.physe.2012.04.003
https://doi.org/10.1016/j.physe.2012.04.003
Autor:
A.I. Diaz Cano, Tetyana Torchynska, Yu. V. Vorobiev, Paul P. Horley, Jesús González-Hernández, P. M. Gorley, Vítor R. Vieira
Publikováno v:
Physica E: Low-dimensional Systems and Nanostructures. 42:2264-2267
We consider semiconductor quantum dots shaped as a rectangular prism and a sphere, in the framework of the effective mass approximation. The Schrodinger equation was solved assuming a specular reflection of a particle from the boundary of the quantum
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::211f06428bf93445e90a4f4d1da44860
https://doi.org/10.1016/j.physe.2010.04.027
https://doi.org/10.1016/j.physe.2010.04.027
Publikováno v:
Journal of Magnetism and Magnetic Materials. 322:1434-1437
One of the important topics in nanomagnetics concerns the use of spin valves for generation of the microwave GHz-frequency oscillations. The power output of an individual spin valve can be increased by synchronization of several devices, which was su
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_________::cb5c40ca8118b5b37e1eab2a31758754
https://doi.org/10.1016/j.jmmm.2009.05.029
https://doi.org/10.1016/j.jmmm.2009.05.029