# Tunneling spectroscopy of localized states of $\mathrm{WS}_2$ barriers in vertical van der Waals heterostructures

## TL;DR

This study investigates localized electronic states in WS2 barriers within van der Waals heterostructures, revealing Coulomb blockade, excited states, and magnetic effects through tunneling spectroscopy.

## Contribution

It provides detailed tunneling spectroscopy of localized states in WS2, highlighting their influence on transport properties and magnetic responses in heterostructures.

## Key findings

- Observation of Coulomb blockade behavior
- Detection of excited states and negative differential resistance
- Extraction of orbital magnetic moments of localized states

## Abstract

In transition metal dichalcogenides, defects have been found to play an important role, affecting doping, spin-valley relaxation dynamics, and assisting in proximity effects of spin-orbit coupling. Here, we study localized states in $\mathrm{WS}_2$ and how they affect tunneling through van der Waals heterostructures of h-BN/graphene/$\mathrm{WS}_2$/metal. The obtained conductance maps as a function of bias and gate voltage reveal single-electron transistor behavior (Coulomb blockade) with a rich set of transport features including excited states and negative differential resistance regimes. Applying a perpendicular magnetic field, we observe a shift in the energies of the quantum levels and information about the orbital magnetic moment of the localized states is extracted.