Hongyi Yu

TL;DR: In this article, the latest advances in valley-tronics have largely been enabled by the isolation of 2D materials (such as graphene and semiconducting transition metal dichalcogenides) that host an easily accessible electronic valley degree of freedom, allowing for dynamic control.

TL;DR: This work reports the unambiguous observation and electrostatic tunability of charging effects in positively charged, neutral and negatively charged excitons in field-effect transistors via photoluminescence and finds the charging energies for X(+) and X(-) to be nearly identical implying the same effective mass for electrons and holes.

TL;DR: The ability to address coherence, in addition to valley polarization, is a step forward towards achieving quantum manipulation of the valley index necessary for coherent valleytronics.

TL;DR: Results suggest that the origin of the observed effects is interlayer excitons trapped in a smooth moiré potential with inherited valley-contrasting physics, and presents opportunities to control two-dimensional moirÉ optics through variation of the twist angle.

TL;DR: This work created interlayer exciton spin-valley polarization by means of circularly polarized optical pumping and determined a valley lifetime of 40 nanoseconds, which enables the visualization of the expansion of a valley-polarized exciton cloud over several micrometers.