Abstract
Dynamical Bloch band suppression is observed for the first time, using cold sodium atoms in a far detuned standing wave of light. This system has well-defined Bloch bands as its energy spectrum, which are modified dynamically by imposing a strong phase modulation of the standing wave. The atoms are prepared in the lowest band, and the spectrum is mapped out by introducing a weak spectroscopic probe that drives transitions between the modified bands. Dynamical suppression of the bands is observed at a critical value of the modulation strength, and is well supported by a full quantum mechanical analysis that goes beyond the single-band and tight-binding approximations.
- Received 19 June 1998
DOI:https://doi.org/10.1103/PhysRevLett.81.5093
©1998 American Physical Society