Vishik Lab: Spectroscopies of Advanced Materials

Department of Physics, University of California Davis

Author: ivishik

Commentary on ARPES studies of quantum materials

The following commentary, written with my postdoc advisor Nuh Gedik, is available online: https://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys4273.html

This commentary is part of an upcoming issue of Nature Physics, focusing on quantum materials, and it discusses the contributions that the experimental technique of angle-resolved photoemission spectroscopy (ARPES) has made to this research area. Quantum materials exhibit a panoply of phenomena, and this diverse class of materials are linked together via a shared paradigm of emergence–the idea that the aggregate many-electron properties of materials cannot be derived from the behavior of a single electron (i.e. more is different). Trying to understand or predict these emergent phenomena drives basic research in this area, but in the future, the fruits of this research may have applications in materials for energy production/harnessing and next-generation electronics.

ARPES directly measures how electrons move in crystalline solids, and can thus pinpoint emergent electronic phenomena with high precision. The present commentary discusses how ARPES experiments have illuminated important physics in three classes of quantum materials (cuprate high temperature superconductors, iron-based high temperature superconductors, topological insulators), and how the challenges presented by these materials have in turn driven the improvement of ARPES experimental technology. One of these state-of-the-art ARPES instruments will be installed in my lab in the next several months!

New faculty Q&A

Teaching and learning: Inna Vishik

Ultrafast optics experiments on electron-doped cuprates

A paper from my postdoc is out!

http://journals.aps.org/prb/abstract/10.1103/PhysRevB.95.115125

https://arxiv.org/abs/1601.06694

Electron-doped cuprates are the lesser-studied siblings of the hole-doped high temperature superconductors.  Though they share copper-oxygen planes with the hole-doped cuprates, they have a phase diagram similar to other unconventional superconductors (heavy fermions, organics, iron-based) with an antiferromagnetic phase that abuts against or possibly coexists with superconductivity.  In this paper we explored antiferromagnetic correlations in thin films of LCCO, using femtosecond pump-probe spectrocopy.  We were sensitive to antiferromagnetic correlations via this optical technique because they open a spectral gap in the band dispersion, and the dynamics of excitation recombination across this gap can give information about timescales over which antiferromagnetic correlations are static and coupling between electrons and high-frequency boson.

Some lighter reading

Here are a few of my recent general-audience articles in Forbes and HuffPo about condensed matter, physics/science research, and metallic hydrogen

These articles and others are generally posted on my Media and contact page

Announcements about courses

  • There is conflicting information about the time for Physics 140A (Winter 2017).  The correct time is Tuesday/Thursday, 12:10-1:30PM, Physics building, room 140.  A syllubus can be found in the Courses section of this website or on Canvas.
  • My portion of the lecture slides for Physics 250 (Special topics: Spectroscopies of quantum materials) is now posted under Courses.  I hope this can be a useful resource for those of you interested in ARPES, time-domain spectroscopeis, and applications of these tools for learning about a variety of quantum materials!

Welcome to my website!

I am excited to start as an assistant professor in the physics department at the University of California Davis, and I am building a lab focused on the growth and study of novel quantum materials, particularly unconventional and high temperature superconductors, correlated electron systems, topological materials, and energy materials.  This lab will use both angle-resolved photoemission spectroscopy (ARPES) and time resolved techniques for elucidating the electronic structure and dynamics of quantum materials such as unconventional superconductors, materials with topological surface state, and 2D materials.   These advanced materials hold promise for revealing new emergent phenomena, elucidating interactions in many body systems, and enabling tomorrow’s electronics and energy resources.