A pure quantum state can be equivalently represented by means of its wave function psi(q) or by the Fermi function g(F)(q,p), with q and p coordinates and conjugate momenta of the system of interest. We show that a Gaussian wave packet can be conveniently visualized in phase space by the curve g(F)(q,p)=0. The change in time of the g(F)=0 curve is calculated for a Gaussian packet evolving freely or under a constant or a harmonic force, and the spreading or shrinking of the packet is easily interpreted in phase space. We also discuss a gedanken prism microscope experiment for measuring the position-momentum correlation. This gedanken experiment, together with the well-known Heisenberg microscope and von Neumann velocimeter, is sufficient to fully determine the state of a Gaussian packet.

Gaussian wave packets in phase space : the Fermi g(F) function / G. Benenti, G. Strini. - In: AMERICAN JOURNAL OF PHYSICS. - ISSN 0002-9505. - 77:6(2009 Jun), pp. 546-551. [10.1119/1.3083268]

Gaussian wave packets in phase space : the Fermi g(F) function

G. Strini
Ultimo
2009

Abstract

A pure quantum state can be equivalently represented by means of its wave function psi(q) or by the Fermi function g(F)(q,p), with q and p coordinates and conjugate momenta of the system of interest. We show that a Gaussian wave packet can be conveniently visualized in phase space by the curve g(F)(q,p)=0. The change in time of the g(F)=0 curve is calculated for a Gaussian packet evolving freely or under a constant or a harmonic force, and the spreading or shrinking of the packet is easily interpreted in phase space. We also discuss a gedanken prism microscope experiment for measuring the position-momentum correlation. This gedanken experiment, together with the well-known Heisenberg microscope and von Neumann velocimeter, is sufficient to fully determine the state of a Gaussian packet.
Gaussian wave packets ; Fermi g function ; correlation measurements
Article (author)
File in questo prodotto:
Non ci sono file associati a questo prodotto.
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2434/70339
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 8
  • ???jsp.display-item.citation.isi??? 6
social impact