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Daniel Walkup

Daniel Walkup is a UMD Postdoctoral Researcher in the Nanoscale Processes and Measurements Group in the Nanoscale Device Characterization Division. He received a B.A. in Physics from Boston University and a Ph.D. in Physics from Boston College. His doctoral research focused on using scanning tunneling microscopy to investigate the electronic structure of materials with strong spin-orbit coupling, including topological insulators and Iridium oxides, in the presence of doping or local strain. Daniel is working with Joseph Stroscio using scanning tunneling microscopy to study the electronic properties of graphene devices at low temperature and in the presence of high magnetic fields.

Selected Publications

  • Strain engineering Dirac surface states in heteroepitaxial topological crystalline insulator thin films. I. Zeljkovic, D. Walkup, B.A. Assaf, K.L. Scipioni, R. Sankar, F. Chou and V. Madhavan, Nature Nanotechnology 10, 849-853 (2015).
  • First-order melting of a weak spin-orbit Mott Insulator into a correlated metal. T. Hogan, D. Walkup, X. Chen, R. Dally, T. Z. Ward, M.P.M. Dean, J. Hill, Z. Islam, V. Madhavan and S.D. Wilson, Physical Review Letters 114, 257203 (2015).
  • Imaging the evolution of metallic states in a correlated iridate. Y. Okada, D. Walkup, H. Lin, C. Dhital, T.-R. Chang, S. Khadka, W. Zhou, H.-T. Jeng, M. Paranjape, A. Bansil, Z. Wang, S.D. Wilson and V. Madhavan, Nature Materials 12, 707-713 (2013)


Achieving µeV tunneling resolution in an in-operando scanning tunneling microscopy, atomic force microscopy, and magnetotransport system for quantum materials research

Johannes Schwenk, Sungmin Kim, Julian Berwanger, Fereshte Ghahari Kermani, Daniel T. Walkup, Marlou R. Slot, Son T. Le, W. G. Cullen, Steven R. Blankenship, Sasa Vranjkovic, Hans Hug, Young Kuk, Franz Giessibl, Joseph A. Stroscio
Research in new quantum materials require multi-mode measurements spanning length scales, correlations of atomic scale variables with macroscopic function, and

Interaction-driven quantum Hall wedding cake-like structures in graphene quantum dots

Christopher Gutierrez, Daniel T. Walkup, Fereshte Ghahari Kermani, Cyprian Lewandowski, Joaquin R. Nieva, Kenji Watanabe, Takashi Taniguchi, Leonid Levitov, Nikolai B. Zhitenev, Joseph A. Stroscio
Interactions amongst relativistic particles underpin exotic behaviours in diverse systems ranging from quark-gluon plasmas to Dirac electron fluids in solids

Helical Level Structure of Dirac Potential Wells

Daniel T. Walkup, Joseph A. Stroscio
In graphene and other massless 2D Dirac materials, Klein tunneling compromises electron confinement, and momentum-space contours can be assigned a Berry phase

An On/Off Berry Phase Switching with Circular Graphene Resonators

Fereshte Ghahari Kermani, Daniel T. Walkup, Christopher Gutierrez, Joaquin R. Nieva, Yue Y. Zhao, Jonathan E. Wyrick, Donat F. Natterer, William G. Cullen, Kenji Watanabe, Takashi Taniguchi, Leonid Levitov, Nikolai B. Zhitenev, Joseph A. Stroscio
Berry phase is an example of anholonomy, where the phase of a quantum state may not return to its original value after its parameters cycle around a closed path
Created July 30, 2019, Updated October 9, 2019