Emergent Negative Differential Resistance with an Undisturbed Topological Surface State

Abstract

Emergent properties in topological insulator heterostructures offer fresh insight not only to understand the system as a whole but also to design new approaches to device engineering at the nanoscale. Here we report the emergent phenomenon of negative differential resistance (NDR) on a topological insulator substrate. Starting with the spin-bearing cobalt fluorophthalocyanine molecule F 16 CoPc as the fundamental building block and the topological insulator (TI) Bi 2 Se 3 as the host, using scanning tunneling spectroscopy (STS) we observe the emergence of NDR at the F 16 CoPc/Bi 2 Se 3 interface at a specific negative bias. The topological surface state is also preserved in the process. Realizing NDR at the molecular scale presents a major advance toward designing ultrafast electron tunneling devices as well as high speed, low power, and compact nanoelectronic devices. The undisturbed topological surface state of Bi 2 Se 3 offers added tunability for computer architectures that can be built concomitantly using the topological surface state and NDR.

Substrate-Dependent Physical Properties at the Interface of Manganese(II) Phthalocyanine and Topological Insulators

“…Taking into account that organic molecules are usually weakly bonded to the substrate, the use of magnetic organic molecules has possibility to solve this problem. Transition metal phthalocyanines (TMPc, TM = Mn, Fe, Co, Ni, and Cu) are typical magnetic organic molecules that show different spin phenomena depending on the center TM atom. , The effect of TMPc adsorption on TIs has been widely studied using scanning tunneling microscopy (STM) and scanning tunneling spectroscopy (STS) ,− but less studied with photoelectron spectroscopy (PES). − …”