Paper

Accessing the spectral function in a current-carrying device

Cacho, Cephise, Taniguchi, Takashi, Ulstrup, Søren, Biswas, Deepnarayan, Muzzio, Ryan, Hofmann, Philip, Sanders, Charlotte E, Singh, Simranjeet, Miwa, Jill A, Curcio, Davide, Jones, Alfred J H, Watanabe, Kenji, Dudin, Pavel, Volckaert, Klara, Katoch, Jyoti

2020

Overview

The presence of an electrical transport current in a material is one of the simplest and most important realisations of non-equilibrium physics. The current density breaks the crystalline symmetry and can give rise to dramatic phenomena, such as sliding charge density waves [1], insulator-to-metal transitions [2,3] or gap openings in topologically protected states [4]. Almost nothing is known about how a current influences the electron spectral function, which characterizes most of the solid's electronic, optical and chemical properties. Here we show that angle-resolved photoemission spectroscopy with a nano-scale light spot (nanoARPES) provides not only a wealth of information on local equilibrium properties, but also opens the possibility to access the local non-equilibrium spectral function in the presence of a transport current. Unifying spectroscopic and transport measurements in this way allows non-invasive local measurements of the composition, structure, many-body effects and carrier mobility in the presence of high current densities.

• Publisher: Cornell University Library, arXiv.org
• Subject: Carrier mobility / Charge density waves / Chemical properties / Composition effects / Current density / Optical properties / Organic chemistry / Photoelectric emission / Spectra