Despina Louca

Ph.D., 1997, Pennsylvania
Maxine S. and Jesse W. Beams Professor of Physics

Experimental Condensed Matter Physics

Research Interests

The interactions of the spin, charge and lattice degrees of freedom often lead to emerging  properties such as spin and charge density waves, superconductivity and quantum spin liquid states. The class of materials that are of interest to the Louca group includes topological insulators and semimetals, spintronic antiferromagnets of the I-Mn-V class, transition metal dichalcogenides, disorder superconductors, layered semiconductors etc.  Understanding the macroscopic functionality of these systems can potentially be very useful for industrial applications. Louca’s research focuses on understanding their responses as a function of temperature, pressure, and magnetic fields by probing the atomic and magnetic structures and dynamics using scattering techniques performed at national and international neutron and X-ray facilities. The group makes use of analysis tools combined with modeling to examine atomic correlations at very small length scales under extreme conditions, probes lattice dynamics and magnetic interactions. The group is also involved with materials synthesis and characterization of the bulk properties.

Graduate Students

Selected Publications

1. "Charge Density Modulation and Defect Ordering in NaMnBi magnetic semimetal", A. Wegner, D. Louca, K. Taddei, J. Neuefeind, D. Louca,  arXiv:2003.00089 (submitted to Phys. Rev. Lett.) (2020).
 
2. "Td to 1T′ structural phase transition in WTe2 Weyl semimetal", Y. Tao, J. A. Schneeloch, A. A. Aczel, and D. Louca, arXiv preprint arXiv:2003.09489 (submitted to Phys. Rev. B Rapid Comm.)  (2020).
 
3. "Evolution of the structural transition in Mo1−xWxTe2", J. A. Schneeloch, Y. Tao, C. Duan, M. Matsuda, A. A. Aczel, J. A. Fernandez-Baca, G. Xu, J. C. Neuefeind, J. Yang and D. Louca, arXiv:2003.08531(submitted to Phys. Rev. B)  (2020).
 
4. "Appearanc of a Td* phase across the Td to 1T′ phase bounday in the Weyl semimetal MoTe2", Y Tao, JA Schneeloch, C Duan, M Matsuda, SE Dissanayake, AA Aczel, Jaime A Fernandez-Baca, Feng Ye, Despina Louca, Physical Review B 100 (10), 100101 (2019).
 
5. "Electronic band tuning under pressure in MoTe2 topological semimetal", S. Dissanayake, C. Duan, J. Yang, J. Liu, M. Matsuda, C. Yue, J. A Schneeloch, J. C. Y. Teo, D. Louca, NPJ Quantum Materials 4 (2019).

6. "Local trigonal modes and the suppression of the charge density wave in TiSe2-xTex", A Wegner, D Louca, J Yang, Physical Review B 99 (20), 205110 (2019).

7.“Emergence of topologically protected states in MoTe2 Weyl semimetal with layer stacking order”, J. A. Schneeloch, C. Duan, J. Yang, J. Liu, X. Wang, and D. Louca, Phys. Rev. B. 99, 161105(R) (2019).

8.“Defect-driven extreme magnetoresistance in an I-Mn-V semiconductor”, J. Yang, A. Wegner, C. M. Brown, and D. Louca, Applied Physics Letters 113, 122105 (2018).     
 
9. “Appearance of superconductivity at the vacancy order-disorder boundary in KxFe2-ySe2”, C. Duan, J. Yang, Y. Ren, S. M. Thomas and D. Louca, Phys. Rev. B 97, 184502 (2018).    
 
10. “Fe vacancy order and domain distribution in AxFe2-ySe2”, C. Duan and D. Louca, J. Supercond. Novel Magn. 31, 757 (2018).   
 
11.“Elastic and electronic tuning of magnetoresistance in MoTe2”, J. Yang, J. Colen, J. Liu, M. C. Nguyen, G.-W. Chern, and D. Louca, Science Advances 3, No. 12, eaao4949 (2017). 
 

News Items

Despina Louca’s group, and in particular graduate student Aaron Wegner and postdoctoral researcher Junjie Yang, has discovered a way to boost the magnetoresistance in the I-Mn-V class of ......More >
Researchers at UVa found a way through strain engineering to manipulate the electronic band structure, and induce large, reversible response of the magnetoresistive properties under high ......More >
Prof. Despina Louca has been elected to serve a four year term as President of the Neutron Scattering Society of America. See  More >
Dear Colleagues,   Peter Arnold and Despina Louca have been elected 2014 APS Fellows. Please join me to say “congratulations” to these two ......More >
Despina Louca, with her colleagues at UT Austin, received one of the three MIRT awards made by the National Science Foundation this year among high competition.The Materials Interdisciplinary ......More >

Honors

President of the Neutron Scattering Society of America [2017-2020]
APS Fellow [2014]
For demonstration of the importance of the local atomic structure for elucidating the physical properties of complex oxides including the transition metal oxides through neutron scattering using the pair-density-function analysis.