Nanowerk August 18, 2022
The phase transition between non-trivial and trivial topological states is important for next-generation technology, such as dissipation-free electronics. A team of researchers in the US (SLAC National Accelerator Laboratory, Stanford University, Harvard University, the State University of New Jersey) has demonstrated that circularly polarized laser-field-driven high-harmonic generation is distinctly sensitive to the non-trivial and trivial topological phases in the prototypical three-dimensional topological insulator bismuth selenide. The phase transition is chemically initiated by reducing the spin–orbit interaction strength through the substitution of bismuth with indium atoms. The phase transition is chemically initiated by reducing the spin–orbit interaction strength through the substitution of bismuth with indium atoms. The origins of the anomalous high-harmonic response were corroborated by calculations using the semiconductor optical Bloch equations with pairs of surface and bulk bands. According to the researchers this method offers sensitivity to the electronic structure of the material, including its nonlinear response, and is compatible with a wide range of samples and sample environments…read more.Â
TECHNICAL ARTICLEÂ
Probing topological phase transitions using HHG. Credit: Nature Photonics (2022)Â