Related Experiment Video
Updated: May 30, 2026

Radio Frequency Magnetron Sputtering of GdBa2Cu3O7−δ/ La0.67Sr0.33MnO3 Quasi-bilayer Films on SrTiO3 (STO) Single-crystal Substrates
Published on: April 12, 2019
Polaronic pseudogap in the metallic phase of La(0.625)Ca(0.375)MnO(3) thin films
Udai Raj Singh1, S Chaudhuri, R C Budhani
1Department of Physics, Indian Institute of Technology Kanpur, Kanpur 208016, India.
Abstract:
The electronic density of states (DOS) of La(0.625)Ca(0.375)MnO(3) (LCMO) strain-free epitaxial thin films with an insulator-metal transition temperature (T(IM)) of 250 K was probed using variable-temperature scanning tunneling microscopy and spectroscopy. We find a depression in the DOS with a finite zero bias conductance (ZBC) signifying a pseudogap in the 78-310 K temperature range. With cooling, the ZBC is found to increase, indicating an increased DOS near E(F). We interpret the pseudogap as a signature of Jahn-Teller polarons while the ZBC change, in agreement with the bulk insulator-metal transition, optical Drude peak and photoemission experiments, indicates the presence of free carriers at the Fermi energy in the metallic phase. The free carriers are discussed in terms of correlated polaronic states.
Related Concept Videos
Dielectric Polarization in a Capacitor
Valence Bond Theory
Biasing of Metal-Semiconductor Junctions
In Schottky junctions, where the semiconductor is n-type, applying a positive voltage to the metal relative to the semiconductor reduces its Fermi...
Potential Due to a Magnetized Object
The vector...
Theory of Metallic Conduction
In this theory, Newton's second law of motion is used to determine the acceleration of an electron in the presence of an applied electric field. Then, its velocity is expressed via this acceleration.
An electron moves through the crystal, containing positive ions,...

