Ultraslow Propagation of Squeezed Vacuum Pulses with Electromagnetically   Induced Transparency
  We have succeeded in observing ultraslow propagation of squeezed vacuum pulses with electromagnetically induced transparency. Squeezed vacuum pulses (probe lights) were incident on a laser cooled 87Rb gas together with an intense coherent light (control light). A homodyne method sensitive to the vacuum state was employed for detecting the probe pulse passing through the gas. A delay of 3.1us was observed for the probe pulse having a temporal width of 10 us. 
Daisuke Akamatsu, Yoshihiko Yokoi, Manabu Arikawa, Satoshi Nagatsuka,   Takahito Tanimura, Akira Furusawa and Mikio Kozuma