Chirality and spin selectivity in Te and other crystals*

Chiral materials, similarly to human hands, have distinguishable right-handed and left-handed enantiomers which may behave differently in response to external stimuli. One of the most intriguing aspects of chirality is its impact on charge-to-spin conversion (CSC) which deals with how the charge currents are converted into spin signals. Interestingly, in many cases chiral materials outperform non-chiral ones in this regard, making this field important for both fundamental and applied physics.

In this talk, I will focus on chiral crystals that showcase chirality-dependent CSC and long-range spin transport. For instance, in trigonal Te, Se, and TaSi₂, electric currents induce an accumulation of spins that align either parallel or anti-parallel to them, resembling the phenomenon of chirality-induced spin selectivity (CISS) found in molecules. These materials not only exhibit efficient CSC, but also possess a so-called persistent spin texture in reciprocal space, potentially contributing to very long spin lifetimes.

Next, I will discuss the potential of chirality-dependent CSC and spin transport in two-dimensional (2D) chiral crystals. These materials can be realized as thin films of three-dimensional materials, such as Te which has a 2D version called tellurene with reduced symmetry. Another possibility is the creation of artificial chiral materials made of twisted van der Waals (vdW) crystals, where twisting in two opposite directions generates left- and right-handed versions of the same system. The abundance of possibilities opens up new perspectives for the design of spintronics devices.