Ultrafast piezospectroscopy in semiconductor nanostructures

摘要

We use the internal picosecond strain pulses to control the electron energy in a semiconductor quantum well. For generating the strain pulse a 100 nm thick metal transducer was hit by intense laser pulse and a strain pulse with duration ～10 ps and amplitude up to 0.1% was injected into a GaAs substrate. This strain pulse travels strongly directed through the crystal towards the quantum well generating at each momentary position a "nano-earthquake". When the quantum well is hit by this "earth quake", the exciton resonance is shifted on a value up to 10 meV on a ps time scale.