THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar: 

   O Centenário da Relatividade Geral 

Prof. Dr. Victor de Oliveira Rivelles

Instituto de Física – USP

 Abstract:

 Apresentaremos um panorama geral de uma das teorias que revolucionaram a física do século XX. Veremos o que levou Einstein a formular a relatividade geral, as mudanças de paradigmas que gerou, seus efeitos mais importantes, dentre eles ondas gravitacionais e buracos negros e como levou ao nascimento de um novo ramo da ciência, a cosmologia.

Date: 13/March/2015 – (friday) – Place: Sala 212 – Auditório do Departamento de Física– Time: 10h15min

Continue a leitura » »

 The Physics Graduate Program invites everyone to:

  Defense of Doctoral Thesis

 Luis Cesar Nunes dos Santos

  Alguns Resultados no Estudo de Férmions e Bósons em Espaços Curvos: Soluções das Equações de Dirac e klein-Gordon

Defense Committee:

 Prof. Dr. Celso de Camargo Barros Junior – (president) – FSC/UFSC

Prof. Dr. Sérgio José Barbosa Duarte – (external member) – CBPF

Prof. Dr. Luis Rafael Benito Castro – (external member) – UFMA

Prof. Dr. Sidney dos Santos Avancini – (membro titular) – UFSC/FSC

Prof. Dr. Eduardo Inacio Duzzioni – (local member) – UFSC/FSC

Prof. Dr. Paulo Juliano Liebgott – (local member) – UFSC/FSC

 Date: 11/March/2015 – wednesday – Times: 9:00 am – Place: Sala 212 – Auditório do Departamento de Física

 THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar: 

   Quantum dipolar gases for quantum magnetism 

Laurent Vernac

Laboratoire de Physique des Lasers / Université Paris 13

Abstract:

Bose Einstein Condensates (BEC) have been obtained with ultra cold atoms in 1995. In these quantum gases all atoms are in the same quantum state, which gives them unique properties in terms of coherence, and allows for observation of matter interference, superfluidity, or transition from superfluid to Mott insulator states in an optical lattice. I will present experimental results obtained in our group with chromium atoms. Due to the high spin (S=3) in the ground state of chromium, there are large magnetic dipole-dipole interactions (DDIs) between the atoms, which are long range, and anisotropic. They confer specific properties to chromium BECs. For example, the excitation spectrum depends on the direction of the magnetic field: a Cr BEC can be seen as an anisotropic superfluid [1]. DDIs allow as well the change of the magnetization of the sample, which leads to spontaneous depolarization of the BEC at low magnetic fields, and multi-components BECs [2,3]. The main part of my talk will be devoted to the results we have obtained in a 3D optical lattice. We have studied spin exchange dynamics due to DDIs in the Mott insulator state, with one or two atoms per lattice site [4]. Our system is well described by an effective XXZ spin Hamiltonian, with Ising and exchange terms. We thus obtain an interesting system for quantum simulation, which realizes a spin model used in condensed matter physics, with true spin-spin interactions. As correlations build up between the few thousands of atoms loaded in the lattice, our system should reveal as well the existence of entanglement between many particles, through the finding of a relevant experimental entanglement witness. I will conclude by perspectives offered by our recent production of a chromium quantum gas with the fermionic isotope (Fermi Sea) [5].

REFS.:

[1] Anisotropic Excitation Spectrum of a Dipolar Quantum Bose Gas G. Bismut et al., Phys. Rev. Lett. 109, 155302 (2012)

[2] Spontaneous demagnetization of a dipolar spinor Bose gas atultra-low magnetic field

B. Pasquiou, Phys. Rev. Lett. 106, 255303 (2011)

[3] Thermodynamics of a Bose-Einstein condensate with free magnetization B. Pasquiou et al., Phys. Rev. Lett., 108, 045307 (2012)

[4] Nonequilibrium Quantum Magnetism in a Dipolar Lattice Gas A. de Paz et al., Phys. Rev. Lett., 111, 185305 (2013)

[5] Chromium Dipolar Fermi SeaB. Naylor et al., Phys. Rev. A 91, 011603(R) (2015)

Date: 6/March/2015 – (friday) – Place: Sala 212 – Auditório do Departamento de Física– Time: 10h15min

The Physics Graduate Program invites everyone to:

 Defence of M.Sc. dissertation

 Ivan Eugênio Cunha

 Matéria Nuclear no Universo Primordial

Defense Commitee

 Prof. Dr. Celso de Camargo Barros Junior – (president) – FSC/UFSC

Prof. Dr. Manuel Maximo Bastos Malheiro de Oliveira – (external member) – ITA

Prof. Dr. José Ricardo Marinelli – (local member) – UFSC/FSC

Prof. Dr. Sidney dos Santos Avancini – (local member) – UFSC/FSC

Nome do Professor – (supplementary member) – USP

 Date: 06/March/2015 – tuesday – Time: 2:00 pm – Place: Sala 212 – Auditório do Departamento de Física

The Physics Graduate Program invites everyone to:

  Defence of M.Sc. dissertation

 William Rafael Tavares

 Excitações Mesônicas sob Influência de Campos Magnéticos Fortes

Defense Commitee

 Prof. Dr. Sidney dos Santos Avancini – (president) – FSC/UFSC

Prof. Dr. Ricardo Luciano Sonego Farias – (external member) – UFSM

Prof. Dr. Celso de Camargo Barros Junior – (local member) – UFSC/FSC

Prof. Dr. Marcus Emmanuel Benghi Pinto – (local member) – UFSC/FSC

Prof. Dr. José Ricardo Marinelli – (local member) – UFSC/FSC

Date: 02/March/2015 – monday – Time: 10:00 am – Place: Sala 212 – Auditório do Departamento de Física

The Physics Graduate Program invites everyone to:

Qualifying Examination for Doctoral Thesis

Eduardo Muller dos Santos

 Dinâmica da Informação de Wigner-Yanase para o Modelo de Superradiância de Dicke

Defense Committee:

  Prof. Dr. Eduardo Inacio Duzzioni – (president) – FSC/UFSC

Prof. Dr. Jonas Maziero – (external member) – UFSM/FSC

Prof. Dr. Marcelo Henrique Romano Tragtenberg – (local member) – UFSC/FSC

Prof. Dr. Kahio Tibério Mazon – (local member) – UFSC/FSC

Prof. Dr. Frederico Firmo de Souza Cruz – (supplementary member) – UFSC/FSC

Date: 27/Frebuary/2015 – friday – Time: 9:00 am – Place: Sala 212 – Auditório do Departamento de Física

Continue a leitura » »