Method for production and identification of Weyl semimetal

A method of producing a TaAs Weyl semimetal, the method comprising:

• providing a tantalum (Ta) powder and an arsenic (As) powder, wherein each of the Ta powder and the As powder has an initial purity of at least 99.9%;
• heating the Ta powder and the As powder to form a polycrystalline TaAs compound, wherein heating eliminates a presence of TaAs2;
• sealing the polycrystalline TaAs compound and a transfer agent in a first end of a closed ampule, wherein the transfer agent is one or more of:
• Snl4 and Tel4;
• and
• heating the closed ampule to about 1073K at the first end and to about 1273K at a second end to produce a temperate gradient along a length of the closed ampule to grow the TaAs Weyl semimetal via a chemical vapor transport (CVT) reaction.

A method of identifying a Weyl semimetal, the method comprising:

• directing vacuum ultraviolet (UV) radiation from an UV radiation source and soft x-ray radiation from an x-ray radiation source onto a material;
• detecting a crescent feature and band dispersions at representative momentum space cuts;
• analyzing, using a hardware processor, the band dispersions to determine that the band dispersions moving in a same direction as energy levels from one or more the of UV radiation source and the x-ray radiation source are varied;
• and
• classifying the material as a Weyl semimetal based on the analyzing.