Generation, transport and detection of valley-locked spin photocurrent in WSe2–graphene–Bi2Se3 heterostructures
| Autor: | Hyunyong Choi, Seunghoon Yang, Chul-Ho Lee, Moon-Ho Jo, Jangyup Son, Soonyoung Cha, Jehyun Kim, Dohun Kim, Wooyoung Shim, Sooun Lee, Jun Sung Kim, Doeon Lee, Minji Noh, Jekwan Lee, Hoil Kim, Sangwan Sim, Ho Seung Shin, Hyemin Bae |
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| Rok vydání: | 2018 |
| Předmět: |
Biomedical Engineering
Bioengineering 02 engineering and technology 01 natural sciences law.invention Computer Science::Robotics law 0103 physical sciences General Materials Science Electrical and Electronic Engineering 010306 general physics Quantum Physics Photocurrent Spin polarization Spintronics Graphene business.industry Transistor Heterojunction 021001 nanoscience & nanotechnology Condensed Matter Physics Atomic and Molecular Physics and Optics Topological insulator Optoelectronics Condensed Matter::Strongly Correlated Electrons 0210 nano-technology business |
| Zdroj: | Nature Nanotechnology. 13:910-914 |
| ISSN: | 1748-3395 1748-3387 |
| DOI: | 10.1038/s41565-018-0195-y |
| Popis: | Quantum optoelectronic devices capable of isolating a target degree of freedom (DoF) from other DoFs have allowed for new applications in modern information technology. Many works on solid-state spintronics have focused on methods to disentangle the spin DoF from the charge DoF1, yet many related issues remain unresolved. Although the recent advent of atomically thin transition metal dichalcogenides (TMDs) has enabled the use of valley pseudospin as an alternative DoF2,3, it is nontrivial to separate the spin DoF from the valley DoF since the time-reversal valley DoF is intrinsically locked with the spin DoF4. Here, we demonstrate lateral TMD–graphene–topological insulator hetero-devices with the possibility of such a DoF-selective measurement. We generate the valley-locked spin DoF via a circular photogalvanic effect in an electric-double-layer WSe2 transistor. The valley-locked spin photocarriers then diffuse in a submicrometre-long graphene layer, and the spin DoF is measured separately in the topological insulator via non-local electrical detection using the characteristic spin–momentum locking. Operating at room temperature, our integrated devices exhibit a non-local spin polarization degree of higher than 0.5, providing the potential for coupled opto-spin–valleytronic applications that independently exploit the valley and spin DoFs. Lateral TMD–graphene–topological insulator hetero-devices enable room-temperature optoelectronic transport of the valley-locked spin polarization degree of freedom. |
| Databáze: | OpenAIRE |
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