Mathias Schubert

Contact Information:

City Campus (Lincoln)
NH E430C
(402) 817-8977
mschubert4@unl.edu
Facebook icon   

Personal Links:

Complex Materials Optics Network

JA Woollam Professor of Engineering

Academic Degrees

  • 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

Certifications

  • Dr. rer. nat., Dr. habil., Dr. tech. h.c.

Recent News

Mathias and collaborators published their paper in nature on Hyperbolic shear polaritons in monoclinic gallium oxide. Read more news at phys.org, pro-physik.de, nature Asia, the The Max Planck Society, The Nebraska EPSCoR Office, The University of Nebraska-Lincoln, The Mirage News, Technology.Org, and Vanderbilt University.

Areas of Research and Professional Interest

  • 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

Research Profiles:

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

Courses Taught

About Mathias Schubert

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 increase the capabilities of this technique. For example, he currently utilizes 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 makes use of techniques such as Raman spectroscopy, SEM, AFM, TEM, XRD and magneto-optic ellipsometry to investigate material surface properties.

Experience

Fellowships:
  • 1995-1997: Studienstiftung des Deutschen Volkes (German National Merit Foundation), Germany
  • 1993-2002: University of Nebraska-Lincoln, U.S.A.
  • 2002: The Swedish Foundation for International Cooperation in Research and Higher Education
  • (STINT), Linköpings universitet/Linköping Institute of Technology, Sweden
  • 2005: (1 mo.) Université Pierre et Marie Curie, Laboratoire d'Optique des Solides, France
Editor Activities (Journals):
  • 2005-2007 & 2014-2017: Journal Optical Society of America A, Topical Editor
  • 2017 - : Applied Physics Letters, Commissioning Editor
Ad-Hoc Reviewing (Journals):

Applied Optics, Applied Physics Letters, European Physical Journal B (condensed matter), IEEE Transactions on Nanotechnology, Journal of Applied Physics, Journal of Materials Research, Journal of Optics A: Pure and Applied Optics, Journal of The Electrochemical Society, Journal of the Optical Society of America A, Journal of Physics D: Applied Physics, Journal of Vacuum Science and Technology, Langmuir, Materials, Science and Engineering B, Measurement, Science and Technology, Optics Communications, Optics Express, Optics Letters, physica status solidi, Physical Review B, Physical Review Letters, Physics Letters A, Review of Scientific Instruments, Surface and Interface Analysis, Thin Solid Films

Conference Organization:
  • Since 2002: Workshop Ellipsometrie

  • Since 2003: Int. Conf. on Spectroscopic Ellipsometry

  • Since 2009: Topical Focus Session Ellipsometry at the Annual American Vacuum Society International Symposium and Exhibition

  • Since 2017: ICMCTF shourt course Ellipsometry

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

Funding

  • Silver Nanoparticles from Nano-food Packaging: A Systematic Characterization, Modeling, and Exposure Assessment, NU Collaborative Research Initiative, NU Collaborative Research Initiative, Co-PI 

  • Emergent Quantum Materials and Technologies (EQUATE), NSF EPSCoR Research Infrastructure Improvement award, Senior-PI

  • Terahertz Electron Paramagnetic Resonance Ellipsometry Defect Characterization in Ultrawideband Gap Monoclinic Gallium Oxide and Related Alloys, DOD-Air Force Off of Sci Rsch, PI

  • Charge carrier dynamics and optical Hall effect in multi-valley semiconductors, DOD-Air Force Off of Sci Rsch, Co-PI

  • The Influence of Doping and Annealing onto the Lattice Dynamics, Band Structure and Free Charge Carrier Properties in Monoclinic Gallium Aluminum Oxide Semiconductor Alloys, NSF, PI

  • The Strain-Stress Relationships for Band Gap, Phonon and Plasmon Energies in Monoclinic Ga2O3 and Related Materials, DOD-Air Force Off of Sci Rsch, PI

  • Wide-bandgap semi-conductors for next generation quantum components, Knut and Alice Wallenbergs Foundation, Co-PI

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, Nature 602, 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]