Multi phonon emission in InAs quantum wells studied with a free electron laser and high pulsed magnetic fields

The short pulsed, tunable output from the Dutch free electron laser FELIX, coupled with a 45 T pulsed magnet has been used to measure the non-radiative decay rates between Landau levels in n-type InAs/GaSb quantum wells. The decay rate is 2 ps−1 when the cyclotron resonance energy, ECR=ELO=30 meV, and only slightly less, 0.8 ps−1 when ECR=2ELO when the principal relaxation pathway is the emission of multiple longitudinal optical (LO) phonons.