Fast topological switch using strained Weyl semimetals
A method of operating a device includes: (1) providing a film of a semimetal in a first topological phase; and (2) inducing interlayer shear oscillation of the semimetal within the film, wherein the interlayer shear oscillation induces the semimetal to transition to a different, second topological phase.
1. A method of operating a device, comprising:
providing a film of a semimetal in a first topological phase; and
inducing interlayer shear displacement of the semimetal within the film, wherein the interlayer shear displacement induces the semimetal to transition to a different, second topological phase,
wherein inducing the interlayer shear displacement includes emitting a set of pulses towards the film, the set of pulses having a field strength of 200 kV/cm or greater in the form of light pulses or electrical pulses.
2. The method of claim 1 , wherein the semimetal is a Weyl semimetal.
3. The method of claim 1 , wherein the semimetal is WTe 2 , MoTe 2 , or Mo 1-x W x Te 2 with x<1.
4. The method of claim 1 , wherein the set of light pulses have a terahertz frequency.
5. The method of claim 1 , wherein the set of light pulses have an infrared wavelength or a visible wavelength.
6. The method of claim 1 , wherein the set of light pulses have a field strength of 1 MV/cm or greater.
7. The method of claim 1 , wherein the interlayer shear displacement has a frequency in a range 0.1 terahertz to 10 terahertz.
8. The method of claim 1 , wherein the transition of the semimetal is associated with a symmetry change between a non-centrosymmetric structure and a centrosymmetric structure.
9. A device comprising:
a film of a semimetal; and
a light source optically coupled to the film and configured to emit a set of light pulses having a field strength of 200 kV/cm or greater, and that is sufficient to induce interlayer shear displacement of the semimetal within the film.
10. The device of claim 9 , wherein the interlayer shear displacement induces the semimetal to transition between a first topological phase and a different, second topological phase.
11. The device of claim 9 , further comprising a substrate, and the film is disposed over the substrate.
12. The device of claim 9 , further comprising a pair of electrodes, and the film is coupled between the pair of electrodes.
13. The device of claim 9 , further comprising a collimator optically coupled between the light source and the film.
14. The device of claim 9 , wherein the semimetal is a Weyl semimetal.
15. The device of claim 9 , wherein the semimetal is WTe 2 , MoTe 2 , or Mo 1-x W x Te 2 with x<1.
16. The device of claim 9 , wherein the light source is a pulsed, terahertz light source.
17. The device of claim 9 , wherein the semimetal is WTe 2 .