Assistant Prof. Phil King
University of St Andrews
6月19号上午十点
唐仲英楼B-501
Methods to generate spin-polarized electronic states in non-magnetic solids are strongly desired to enable all-electrical manipulation of electron spins for new quantum devices. This is generally accepted to require breaking global structural inversion symmetry. In contrast, I will report our observation from spin- and angle-resolved photoemission spectroscopy of spin-polarized bulk states in the centrosymmetric transition-metal dichalcogenide 2H-WSe2 [1]. I will show how this occurs due to local inversion symmetry breaking within constituent sub-units of the bulk crystal where the electronic states are localized, allowing enormous spin splittings of up to ~0.5 eV to develop with a spin texture that is strongly modulated in both real and momentum space. Through this, our study provides direct experimental evidence for a putative locking of the spin with the layer and valley pseudospins in transition-metal dichalcogenides, of key importance for using these compounds in proposed valleytronic devices.
University of St Andrews（圣安德鲁斯大学 ）：该校建立于1410年到1413年，是苏格兰第一所大学，同时也是英语世界中第三古老的大学，仅次于牛津大学与剑桥大学。圣安德鲁斯大学多次被泰晤士报和星期日泰晤士报评为英国或苏格兰年度大学。在苏格兰更是长期占据第一名，是英国的顶级学府之一。