# Ilya Vekhter

#### Professor of Physics

Ph.D., 1998 - Brown University

Louisiana State University

Department of Physics & Astronomy

210-E Nicholson Hall, Tower Dr.

Baton Rouge, LA 70803-4001

225-578-0598-Office

vekhter@phys.lsu.edu **Personal Home Page**

### Research Interests

#### Condensed Matter Theory

Condensed matter physics studies properties of vast numbers of interacting electrons in solids. As a result of the interactions, materials exhibit emergent collective properties: the behavior of a 1mm sample when probed in experiment is very different from the response of individual atoms that make up the material. The collective properties are a consequence of order: in simple solids it is the arrangement of atoms in a regular crystal lattice that gives rise to its rigidity and also determines whether the material is a metal or an insulator. A plethora of different, and often more exotic, orders occurs in more complicated systems: from magnetic and charge to superconductivity and the "hidden" order.

The challenge of condensed matter physics is to understand how this fantastic complexity
of behavior arises from basic quantum mechanics governing the motion of electrons,
and to find an effective way to understand and describe the emergent properties. Theoretical
approaches combine statistical physics (there are ~10^{23} electrons per cubic centimeter in a typical solid), quantum mechanics (electrons
are fermions, which means that they avoid each other when filling up energy levels,
and at or below room temperature they behave as quantum-mechanical particles), and
treatments of strong interactions of many particles.

In my research I analyze the consequences of unusual orders on the experimentally measured quantities, use the experimental data to draw conclusions about the origin of the unconventional properties of strongly interacting electron systems, and investigate theoretical models for emergence of different types of exotic orders, their competition and coexistence. I am especially interested in the unconventional superconductivity in high-temperature copper oxide superconductors and heavy fermion materials and interplay of superconductivity and itinerant magnetism in these systems. I am also investigating the properties of materials near the Quantum Critical Points: points where a phase transition between two different ground states occurs at T=0 and and is accompanied by quantum mechanical fluctuations.

### Current and Select Publications

- "Magnetic Intragap States and Mixed Parity Pairing at the Edge of Spin-Triplet Superconductors"
Alfonso Romano, Paola Gentile, Canio Noce, Ilya Vekhter, and Mario Cuoco,
*Phys. Rev. Lett.***110**, 267002 (2013). - "Inhomogeneous Superconducting States of Mesoscopic Thin-Walled Cylinders in External
Magnetic Fields" K. Aoyama, R. Beaird, D. E. Sheehy, and I. Vekhter,
*Phys. Rev. Lett.***110**, 177004 (2013). - "Heavy Antiferromagnetic Phases in Kondo Lattices" L. Isaev and I. Vekhter,
*Phys. Rev. Lett.***110**, 026403 (2013). - "Structure of magnetic order in Pauli limited unconventional superconductors" Yasuyuki
Kato, C. D. Batista, and I. Vekhter,
*Phys. Rev. B***86**, 174517 (2012). - "Impurity states in multiband s-wave superconductors: Analysis of iron pnictides"
R. Beaird, I. Vekhter, and Jian-Xin Zhu,
*Phys. Rev. B***86**, 140507(R) (2012). - "Theory of quasiparticle vortex bound states in iron-based superconductors: Application
to scanning tunneling spectroscopy of LiFeAs" Yan Wang, Peter J. Hirschfeld, and Ilya
Vekhter,
*Phys. Rev. B***85**, 020506(R) (2012). - "Kondo effect in the presence of spin-orbit coupling" L. Isaev, D. F. Agterberg, and
I. Vekhter,
*Phys. Rev. B***85**, 081107(R) (2012).