Affiliation:
1. Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie, Max-Born-Strasse 2A, 12489 Berlin, Germany.
Abstract
Spin and valley indices represent the key quantum labels of quasi-particles in a wide class of two-dimensional materials and form the foundational elements of the fields of spintronics and valleytronics. Control over these degrees of freedom, therefore, remains the central challenge in these fields. Here, we show that femtosecond laser light combining optical frequency circularly polarized pulse and a terahertz (THz) frequency linearly polarized pulse, a so-called “hencomb” pulse, can generate precisely tailored and 90% pure spin currents for the dichalcogenide WSe
2
and >75% pure valley currents for bilayer graphene with gaps greater than 120 millielectron volts (dephasing time, 20 femtoseconds). The frequency of the circular light component and the polarization vector of the THz light component are shown to represent the key control parameters of these pulses. Our results thus open a route toward light control over spin/valley current states at ultrafast times.
Publisher
American Association for the Advancement of Science (AAAS)
Cited by
4 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献