Dependence of effective mass on spin and valley degrees of freedom.
We measure the effective mass (m) of interacting two-dimensional electrons confined to an AlAs quantum well while we change the conduction-band valley occupation and the spin polarization via the application of strain and magnetic field, respectively. Compared to its band value, m is enhanced unless the electrons are fully valley- and spin-polarized. Incidentally, in the fully spin- and valley-polarized regime, the electron system exhibits an insulating behavior.
Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
T
T
Gokmen
Medini
M
Padmanabhan
M
M
Shayegan