title: Long-Lived Valley Polarization of Intravalley Trions in Monolayer WSe_{2}.
abstract: We investigate valley dynamics associated with trions in monolayer tungsten diselenide (WSe_{2}) using polarization resolved two-color pump-probe spectroscopy. When tuning the pump and probe energy across the trion resonance, distinct trion valley polarization dynamics are observed as a function of energy and attributed to the intravalley and intervalley trions in monolayer WSe_{2}. We observe no decay of a near-unity valley polarization associated with the intravalley trions during ∼ 25  ps, while the valley polarization of the intervalley trions exhibits a fast decay of ∼4  ps. Furthermore, we show that resonant excitation is a prerequisite for observing the long-lived valley polarization associated with the intravalley trion. The exceptionally robust valley polarization associated with resonantly created intravalley trions discovered here may be explored for future valleytronic applications such as valley Hall effects.
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Akshay
authors.initials: A
authors.lastname: Singh
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Kha
authors.initials: K
authors.lastname: Tran
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin 10623, Germany.
authors.forename: Mirco
authors.initials: M
authors.lastname: Kolarczik
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Joe
authors.initials: J
authors.lastname: Seifert
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Yiping
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Kai
authors.initials: K
authors.lastname: Hao
authors.affiliation: Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.
authors.forename: Dennis
authors.initials: D
authors.lastname: Pleskot
authors.affiliation: Department of Physics and Astronomy, University of California, Riverside, California 92521, USA.
authors.forename: Nathaniel M
authors.initials: NM
authors.lastname: Gabor
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin 10623, Germany.
authors.forename: Sophia
authors.initials: S
authors.lastname: Helmrich
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin 10623, Germany.
authors.forename: Nina
authors.initials: N
authors.lastname: Owschimikow
authors.affiliation: Institut für Optik und Atomare Physik, Technische Universität Berlin, Berlin 10623, Germany.
authors.forename: Ulrike
authors.initials: U
authors.lastname: Woggon
authors.affiliation: Department of Physics and Center for Complex Quantum Systems, University of Texas at Austin, Austin, Texas 78712, USA.
authors.forename: Xiaoqin
authors.initials: X
authors.lastname: Li