2023/04/18 by Jinyu Liu, Liu, Jinyu, Yinong Zhou +25
Materials Science · Physics and Astronomy · #Diamond and Carbon-based Materials Research #Electronic and Structural Properties of Oxides #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Topological Materials and Phenomena
paper · pdf · doi:10.48550/arxiv.2304.09072
openalex publication_date 2023/04/18 · openalex created_date 2023/04/22 · openalex updated_date 2026/08/01
Controlling materials to create and tune topological phases of matter could potentially be used to explore new phases of topological quantum matter and to create novel devices where the carriers are topologically protected. It has been demonstrated that a trivial insulator can be converted into a topological state by modulating the spin-orbit interaction or the crystal lattice. However, there are limited methods to controllably and efficiently tune the crystal lattice and at the same time perform electronic measurements at cryogenic temperatures. Here, we use large controllable strain to demonstrate the topological phase transition from a weak topological insulator phase to a strong topological insulator phase in high-quality HfTe5 samples. After applying high strain to HfTe5 and converting it into a strong topological insulator, we found that the sample's resistivity increased by more than two orders of magnitude (24,000%) and that the electronic transport is dominated by the topological surface states at cryogenic temperatures. Our findings show that HfTe5 is an ideal material for engineering topological properties, and it could be generalized to study topological phase transitions in van der Waals materials and heterostructures. These results can pave the way to create novel devices with applications ranging from spintronics to fault-tolerant topologically protected quantum computers.