Electrical Control of Ultra-long Spin-Valley Polarization of Trions in Monolayer Molybdenum Ditelluride

We systematically investigated the electrically-tunable valley polarization mechanism in monolayer MoTe2 by helicity-resolved photoluminescence and ultrafast pump-probe spectroscopy. We observed an ultra-long trion valley lifetime of over 600 ps, the longest for a 2D material.