Volume 135, Number 3, August 2021
|Number of page(s)||7|
|Section||Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties|
|Published online||24 September 2021|
Orbitronics: Orbital currents in solids
1 Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA 52425 Jülich, Germany
2 Institute of Physics, Johannes Gutenberg University Mainz - 55099 Mainz, Germany
3 Department of Physics, Pohang University of Science and Technology - Pohang 37673, Korea
4 Graduate School of Excellence Materials Science in Mainz - 55128 Mainz, Germany
5 Center for Quantum Spintronics, Department of Physics, Norwegian University of Science and Technology NO-7491 Trondheim, Norway
Received: 18 July 2021
Accepted: 13 September 2021
In solids, electronic Bloch states are formed by atomic orbitals. While it is natural to expect that orbital composition and information about Bloch states can be manipulated and transported, in analogy to the spin degree of freedom extensively studied in past decades, it has been assumed that orbital quenching by the crystal field prevents significant dynamics of orbital degrees of freedom. However, recent studies reveal that an orbital current, given by the flow of electrons with a finite orbital angular momentum, can be electrically generated and transported in wide classes of materials despite the effect of orbital quenching in the ground state. Orbital currents also play a fundamental role in the mechanisms of other transport phenomena such as spin Hall effect and valley Hall effect. Most importantly, it has been proposed that orbital currents can be used to induce magnetization dynamics, which is one of the most pivotal and explored aspects of magnetism. Here, we give an overview of recent progress and the current status of research on orbital currents. We review proposed physical mechanisms for generating orbital currents and discuss candidate materials where orbital currents are manifest. We review recent experiments on orbital current generation and transport and discuss various experimental methods to quantify this elusive object at the heart of orbitronics —an area which exploits the orbital degree of freedom as an information carrier in solid-state devices.
© 2021 EPLA
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.