Closed formulas for tunneling time in superlattices

Authors
Citation
P. Pereyra, Closed formulas for tunneling time in superlattices, PHYS REV L, 84(8), 2000, pp. 1772-1775
Citations number
15
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
84
Issue
8
Year of publication
2000
Pages
1772 - 1775
Database
ISI
SICI code
0031-9007(20000221)84:8<1772:CFFTTI>2.0.ZU;2-M
Abstract
New formulas for an exact and simple evaluation of the phase time associate d with the passage of electrons or photons through a finite superlattice ar e derived. This time, named here the superlattice-tunneling time tau(n), ex hibits a resonant-band structure or a superluminal phase time behavior depe nding on whether the particle's energy lies in a band or a gap. In the band , tau(n) remains larger than the free motion time tau(f), while in the gap it can be less than tau(f) (with strong substrate effects), but it is large r than the single-cell phase time tau(l). Extremely good agreements with op tical-pulse and superluminal delay times measured by Spielmann et al. and S teinberg et al, are found, including the superlattice-tunneling-time limit and the substrate effects. Conditions for measurements of earlier electron arrival are also analyzed.