Observation of Large Long-Lived Electron-Hole Drops in Germanium

Alfvén-wave resonances are used to measure time decay of the electron-hole drop radius in stressed Ge, and striking new properties of the condensate are observed. Compared to standard results, the drop volume is larger by more than 1000, and the drop lifetime is increased from 40 μsec to over 400 μsec. We believe the long-lived condensate corresponds to low-density Ge $〈111〉$ or Ge $〈110〉$ phases with one or two electron ellipsoids occupied.