Topological Insulators, The Strange Solids with Conducting Surfaces and Insulating Hearts
In condensed matter physics, topological insulators have captivated scientists for offering a paradoxical behavior: their interiors (bulk) act as insulators, while their edges or surfaces conduct electricity with little resistance. This unusual property arises from topological protection: the conducting surface states are preserved by fundamental symmetries such as time-reversal symmetry and spin–orbit coupling. While the…