Charla: Mechanics of Quantum Crystals: Insight from Quantum Monte Carlo Simulations

17 de febrero de 2017, 17:20.

Charla: Mechanics of Quantum Crystals: Insight from Quantum Monte Carlo Simulations

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El lunes 20 a las 14:30 hs en el aula 209 el Prof. Maurice de Koning, Universidad Estadual de Campinas, Brasil, brindará la Charla: Mechanics of Quantum Crystals: Insight from Quantum Monte Carlo Simulations.

Breve reseña profesional del Prof. Maurice de Koning: Ph.D. Physics UNICAMP, Visiting Engineer 1998-2000 en MIT, Visiting Scientist 2000-2003, Lawrence Livermore National Lab, 2003-2005 Visiting Scientist USP, 2005-Actualidad UNICAMP, actualmente Prof. Asociado.

Charla: Mechanics of Quantum Crystals:
Insight from Quantum Monte Carlo Simulations


The mechanical behavior of quantum crystals, in which the magnitude of the zero-point kinetic energy is appreciable compared to the energy scale of the interatomic interactions, has become a topic of increasing interest. A system that has received particularly significant attention is crystalline 4He, the prototypical bosonic quantum crystal. After initial indications of superfluidity in this crystal, extensive experimental effort has been directed toward the mechanical properties of this system. Indeed, observations of elastic stiffening and giant plasticity have been linked to dislocation behavior and the role of isotopic 3He impurities. Despite an extensive body of experimental data, their interpretation has systematically relied on assumptions concerning the involved fundamental materials parameters, which are inaccessible experimentally. Here, we show how fully atomistic path-integral Monte Carlo (PIMC) simulations can be used to gain insight into the basic deformation mechanisms involved in systems dominated by quantum effects. In addition to addressing the ideal strength of defect-free 4He crystals [1], we discuss the basic structure and mobility of dislocations [2], which are the crystal defects that mediate plastic deformation in crystalline solids. 

[1] E.J Landinez Borda, W. Cai and M. de Koning, Phys. Rev. Lett. 112, 155303 (2014).
[2] E.J Landinez Borda, W. Cai and M. de Koning, Phys. Rev. Lett. 117, 045301 (2016).