Complementarity of perturbations driving insulator-to-metal transition in a charge ordered manganite

TL;DR

This study demonstrates how electric, magnetic, and photon perturbations can collectively induce and enhance an insulator-to-metal transition in a specific charge-ordered manganite thin film, revealing their complementary roles.

Contribution

It establishes the combined effects of electric, magnetic, and photon fields in driving and enhancing the insulator-metal transition in a charge-ordered manganite.

Findings

Photon flux significantly increases conductivity.

Electric and magnetic fields cause persistent conductivity enhancement.

Parallel application of fields amplifies the transition effects.

Abstract

Modulation of charge carrier dynamics and hence electrical conductivity of solids by photoexcitation has been a rich field of research with numerous applications. Similarly, electric and magnetic field assisted enhancement of conductivity are of fundamental importance and technological use. Hole doped manganites of the type (A$_{1-x}$B$_{x})$MnO$_{3}$, where A and B are rare and alkaline earth metals respectively have the distinction of showing all three effects. Here we establish the complementarity of the electric, magnetic and photon fields in driving an insulator-metal transition in epitaxial thin films of La$_{0.175}$Pr$_{0.45}$Ca$_{0.375}$MnO$_{3}$ whose electrical ground state is insulating. Both pulsed and CW lasers cause a giant photon flux dependent enhancement of conductivity. It is further observed that electric and magnetic fields trigger the persistent enhancement of conductivity whose magnitude can be accentuated by application of these fields in parallel.