Due to the small masses of the atoms and the weak interatomic binding, solid 4He is a prototype of what is called a quantum solid, that is a solid in which atoms, due to their zero-point motion, execute very large amplitude vibrations around their lattice sites and explore a sizeable fraction of the primitive cells. This fact opens a scenario in which processes like exchanges between particles or delocalized defects are allowed; such processes could in principle allow one to observe, in a macroscopic domain, phenomena displaying the fundamental laws of Quantum Mechanics which governs the microphysics of the system. By means of a Monte Carlo technique, the Shadow Path Integral Ground State method, which allows one to evaluate exact properties of the T=0K physics of the system, we are studying the properties of the system when vacancies are present; such point-defects could play a very important role in a probable transition to a “supersolid” phase.
A causa della piccola massa degli atomi e della debole interazione tra di essi, un campione di atomi di 4He costituisce un prototipo di quello che viene solitamente definito solido quantistico, cioè un solido i cui atomi, grazie al moto di punto zero, compiono delle oscillazioni di notevole ampiezza attorno alle relative posizioni reticolari esplorando una vasta regione della cella elementare. Ciò dà luogo a uno scenario in cui divengono possibili processi quali scambi tra le particelle e delocalizzazione di difetti, che possono rendere “visibili” a livello macroscopico le leggi della meccanica quantistica che governano la fisica del sistema. Attraverso una tecnica Monte Carlo, il metodo “shadow path integral ground state”, che rende possibile il calcolo esatto di alcune proprietà del sistema a T=0 K, stiamo indagando la fisica del sistema in presenza di vacanze, difetti puntuali che potrebbero giocare un ruolo molto importante in una possibile transizione a una fase supersolida.
The shadow path integral ground state: new light into the physics of quantum solids / E. Vitali, D.E. Galli, L. Reatto - In: Research activities on high performance computing clusters at CILEA 2006[s.l] : CILEA, 2006. - ISBN 9788888971124. - pp. 105-120
The shadow path integral ground state: new light into the physics of quantum solids
E. VitaliPrimo
;D.E. GalliSecondo
;L. ReattoUltimo
2006
Abstract
Due to the small masses of the atoms and the weak interatomic binding, solid 4He is a prototype of what is called a quantum solid, that is a solid in which atoms, due to their zero-point motion, execute very large amplitude vibrations around their lattice sites and explore a sizeable fraction of the primitive cells. This fact opens a scenario in which processes like exchanges between particles or delocalized defects are allowed; such processes could in principle allow one to observe, in a macroscopic domain, phenomena displaying the fundamental laws of Quantum Mechanics which governs the microphysics of the system. By means of a Monte Carlo technique, the Shadow Path Integral Ground State method, which allows one to evaluate exact properties of the T=0K physics of the system, we are studying the properties of the system when vacancies are present; such point-defects could play a very important role in a probable transition to a “supersolid” phase.File | Dimensione | Formato | |
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