Mathias Schubert

Professor Electrical & Computer Engineering University of Nebraska-Lincoln

Address: SEC C290S
Lincoln, NE 68588-0511
Phone: 402-472-3771 On-campus 2-3771
Email: mschubert4@unl.edu

Dr. Mathias Schubert has taught and conducted research at the University of Nebraska-Lincoln for over 15 years. Before becoming a faculty member at the university, Dr. Schubert did research in Sweden, France, Germany, and Switzerland.

Dr. Schubert has investigated such phenomena as the optical Hall effect in semiconductors, the polarization coupling at the interfaces of piezoelectric materials, the spontaneous surface charge accumulation in spontaneous polarization materials, the plasmon-phonon coupling in multinary zincblende-, wurtzite-, rocksalt-, chalcogenide- and perovskite structure materials, and form-induced optical anisotropy in nanostructure materials. Ellipsometry is a material-probing technique often used by Dr. Schubert, and he continually explores ways to enhance its capabilities. For example, he currently uses ellipsometers and quartz crystal microbalances simultaneously to measure thin-film evolution, and Terahertz ellipsometers to detect charge-carrier channels in electronic devices.

Dr. Schubert also uses techniques such as Raman spectroscopy, SEM, AFM, TEM, XRD, and magneto-optic ellipsometry to investigate surface properties of materials.

Education

Privatdozent (Physics), Universität Leipzig, 2003
Dr. habil. (Physics), Universität Leipzig, 2003
Dr. rer. nat. (Physics), Universität Leipzig, 1997
Diplom-Physiker, Universität Leipzig, 1994
Study of Physics, Universität Leipzig, 1989-1994

Research and Professional Interests

Optical Hall-effect in semiconductors
Interface polarization coupling
Form-induced optical anisotropy in nanostructure materials
Ellipsometric instrumentation development
New chemical, biochemical, and biological sensing and separation principles
THz electron paramagnetic resonance ellipsometry
Physics of low-symmetry crystalline materials

Inventions/Patents

Method of obtaining micrographs of transparent specimens using anisotropic contrast, T. Hofmann, M. Schubert, T. Kasputis, A. K. Pannier, C. M. Herzinger, and J. A. Woollam, U.S. Patent No. 10026167 B1, (2018)
Integrated mid-infrared, far infrared, and terahertz optical Hall effect (OHE) instrument, and method of use, Patent number: US 9851294 B1, Type: Grant, Filed: June 24, 2015, Date of Patent: Aug. 18 2014, Assignees: J.A. Woollam Co., Inc., University of Nebraska Board of Regents, Inventors: Tino Hofmann, Mathias M. Schubert, Stefan Schoeche, Sean Knight, Craig M. Herzinger, John A. Woollam, Greg K. Pribil, Thomas E. Tiwald
Optical sensing and separation based on ordered three-dimensional nanostructured surfaces, Patent number: 9739710, Type: Grant, Filed: October 15, 2013, Date of Patent: August 22, 2017, Assignee: NUtech Ventures, Inventors: Mathias M. Schubert, Tino Hofmann, Daniel Schmidt, Patrick H. Dussault, Andrea Holmes, Rebecca Y. Lai
TERAHERTZ-INFRARED ELLIPSOMETER SYSTEM, AND METHOD OF USE, , Publication number: 20150153230, Type: Application, Filed: March 7, 2013, Publication date: June 4, 2015, Applicants: REGENTS OF THE UNIVERSITY OF NEBRASKA (50%), J.A.WOLLAM CO. (50%), Inventors: Craig M. Herzinger, Mathias M. Schubert, Tino Hofmann, Martin M. Liphardt, John A. Woollam
Polarization-coupled ferroelectric unipolar junction memory and energy storage device, Patent number: 8711599, Type: Grant, Filed: October 4, 2011, Date of Patent: April 29, 2014, Assignee: NUtech Ventures, Inventors: Mathias M. Schubert, Tino Hofmann, Venkata Rao Voora
Terahertz resonator, Patent number: 8507860, Type: Grant, Filed: May 20, 2010, Date of Patent: August 13, 2013, Assignee: NUtech Ventures, Inventors: Eva Schubert, Mathias M. Schubert, Tino Hofmann
Mass sensor, Patent number: 8441635, Type: Grant, Filed: March 23, 2010, Date of Patent: May 14, 2013, Assignee: NUtech Ventures, Inventors: Mathias M. Schubert, Eva Schubert, Tino Hofmann, Daniel Schmidt
Empirical correction for spectroscopic ellipsometric measurements of rough or textured surfaces, Patent number: 8248607, Type: Grant, Filed: August 3, 2010, Date of Patent: August 21, 2012, Assignees: J.A. Woollam Co., Inc., Board of Regents of Nebraska University, Inventors: Craig M. Herzinger, Blaine D. Johs, Mathias M. Schubert, Tino Hofmann

Honors and Awards

Renamed Adjunct Professor (Fellow), IPF Dresden, 2018-2020
J.A.Woollam Distinguished University Professorship
Renamed Adjunct Professor (Fellow), IPF Dresden, 2016-2018
Honorary doctorate, University of Linkoping, Sweden 2015
Adjunct Professor (Fellow), Leibniz Institute for Polymer Research (IPF), Germany, 2014-2016
Fellow, American Physical Society 2011
Outstanding Reviewer recognition award Acta Materialia 2011
LIMAT visiting Professor, University Bern-Fribourg, Fribourg, Switzerland 2009
SFB762 Visiting Research Professor, University Leipzig, FRG 2008, 2009
Research Fellow, Université Pierre et Marie Curie, France, 2005
Ludwig-Genzel-Award 2006
Research Fellowship of the Swedish Foundation for International Cooperation in Research and Higher Education 2002
Fellowship, German National Academic Foundation 1994-1997

Selected Publications

Hyperbolic Shear Polaritons in Low-Symmetry Crystals N. Passler, X. Ni, G. Hu, J. R. Matson, M. Wolf, M. Schubert, A. Alù, J. D. Caldwell, T. G. Folland, and A. Paarmann, Nature602, 595 (2022) [DOI-link]

Featured
A Review of Band Structure and Material Properties of Transparent Conducting and Semiconducting Oxides: Ga2O3, Al2O3, In2O3, ZnO, SnO2, CdO, NiO, CuO, and Sc2O3, J. A. Spencer, A. L. Mock, A. G. Jacobs, M. Schubert, Y. Zhang, and M. J. Tadjer, Appl. Phys. Rev. 9, 011315 (2022) [DOI-link]

Linear strain and stress potential parameters for the three fundamental band to band transitions in β-Ga2O3, R. Korlacki, J. Knudtson, M. Stokey, M. J. Hilfiker, V. Darakchieva, and M. Schubert, Appl. Phys. Lett. 120, 042103 (2022) [DOI-link]

Terahertz electron paramagnetic resonance generalized spectroscopic ellipsometry: The magnetic response of the nitrogen defect in 4H-SiC, M. Schubert, S. Knight, S. Richter, P. Kuehne, V. Stanishev, A. Ruder, M. Stokey, R. Korlacki, K. Irmscher, P. Neugebauer, and V. Darakchieva, Appl. Phys. Lett. 120, 102101 (2022) [DOI-link]

Broadband enhanced chirality with tunable response in hybrid plasmonic helical metamaterials, U. Kilic, M. Hilfiker, A. Ruder, R. Feder, E. Schubert, M. Schubert, and C. Argyropoulos, Advanced Functional Materials , 2010329 (2021) [DOI-link]

Stretchable Thin Film Mechanical Strain Gated Switches and Logic Gate Functions Based on a Soft Tunneling Barrier, S. Chae, W. J. Choi, I. Fotev, E. Bittrich, P. Uhlmann, M. Schubert, D. Makarov, J. Wagner, A. Pashkin, and A. Fery, Advanced Materials Wiley , 2104769 (2021) [DOI-link]

Strain and stress relationships for optical phonon modes in monoclinic crystals with β-Ga₂O₃ as an example, R. Korlacki, M. Stokey, A. Mock, S. Knight, A. Papamichail, V. Darakchieva, and M. Schubert, Phys. Rev. B 102, 180101(R) (2020) [DOI-link]

Mueller matrix ellipsometer using dual continuously rotating anisotropic mirrors, A. Ruder, B. Wright, D. Peev, R. Feder, U. Kilic, M. Hilfiker, C. M. Herzinger, and M. Schubert, Opt. Lett. 45, 3541-3544 (2020) [DOI-link]

Editors' Pick
Anisotropic quasi-static permittivity of single-crystal β-Ga₂O₃, P. Gopalan, S. Knight, A. Chanana, M. Stokey, P. Ranga, M. Scarpulla, S. Krishnamoorthy, V. Darakchieva, Z. Galazka, K. Irmscher, A. Fiedler, S. Blair, M. Schubert, and B. S. Rodriguez, Appl. Phys. Lett. 117, 252103 (2020) [DOI-link]

Phonon order and reststrahlen bands of polar vibrations in crystals with monoclinic symmetry, M. Schubert, A. Mock, R. Korlacki, and V. Darakchieva, Phys. Rev. B 99, 041201 (Rapid Comm.) (2019) [DOI-link]

Editors' Pick
Longitudinal phonon plasmon mode coupling in β-Ga₂O₃, M. Schubert, A. Mock, R. Korlacki, S. Knight, Z. Galazka, G. Wagner, V. Wheeler, M. Tadjer, K. Goto, and V. Darakchieva, Appl. Phys. Lett. 114, 102102 (2019) [DOI-link]