Kai Liu

Prof. Kai Liu

Professor and Robert L. McDevitt, K.S.G., K.C.H.S. and Catherine H. McDevitt, L.C.H.S. Chair in Physics

Office: 544 Reiss Science Building
Lab: 111-117 Regents Hall
Telephone: (202) 687-6135
E-mail: kai.liu@georgetown.edu

Website: Group Page; Curriculum Vitae; Publications; Web of Science; Google Scholar.

Prof. Kai Liu received his Ph.D. in Physics from the Johns Hopkins University in 1998. He then carried out postdoctoral research at the University of California – San Diego. He joined the University of California – Davis faculty in 2001, where he was promoted to Associate Professor in 2005 and Professor in 2008.  He transitioned to the Georgetown University during 2018-19. Prof. Liu was recipient of an Alfred P. Sloan Research Fellowship (2005) and a UC Davis Chancellor’s Fellowship (2007). He is an elected Fellow of the Institute of Physics (UK, 2011), American Physical Society (2012), IEEE (2016), American Association for the Advancement of Science (2019), and the National Academy of Inventors (2022).  He served as the Program Co-Chair for the 2007 Annual Conference on Magnetism and Magnetic Materials in Tampa (2007 MMM) and the 2011 International Magnetics Conference in Taipei (2011 Intermag), as the General Chair for the 2016 MMM in New Orleans, and as an Associate Editor for APL Materials (2018-19). He is currently Chair of the International Union of Pure and Applied Physics (IUPAP) Commission on Magnetism.

Current Research

Prof. Liu’s research focuses on synthesis and experimental investigation of nanostructured materials, particularly in nanomagnetism and spintronics, which have potential applications in magnetic recording, low dissipation information storage and nanoelectronics. Current research topics include: Topological spin textures such as magnetic skyrmions and chiral domain walls; Magneto-ionic control of metal/oxide interfaces towards energy-efficient nanoelectronics and neuromorphics; High magnetic anisotropy materials such as L10 FePt for the emerging heat-assisted magnetic recording media; 3D networks for information storage; Low density metallic foams for hydrogen storage and air filtration, etc.

Selected Recent Publications

C. J. Jensen, A. Quintana, P. Quarterman, A. J. Grutter, P. P. Balakrishnan, H. R. Zhang, A. Davydov, X.X. Zhang, and Kai Liu, “Nitrogen-Based Magneto-Ionic Manipulation of Exchange Bias in CoFe/MnN Heterostructures”, ACS Nano, 17, 6745-6753 (2023).

D. Bhattacharya, Z. J. Chen, C. J. Jensen, C. Liu, E. C. Burks, D. A. Gilbert, X.X. Zhang, G. Yin, and Kai Liu, “3D Interconnected Magnetic Nanowire Networks as Potential Integrated Multistate Memristors”, Nano Letters, 22, 10010-10017 (2022).

G. Chen, C. Ophus, R. Lo Conte, R. Wiesendanger, G. Yin, A. K. Schmid, and Kai Liu, “Ultrasensitive Sub-monolayer Palladium Induced Chirality Switching and Topological Evolution of Skyrmions”, Nano Letters, 22, 6678-6684 (2022).

G. Chen, C. Ophus, A. Quintana, H. Y. Kwon, C. Y. Won, H. F. Ding, Y. Z. Wu, A. K. Schmid, and Kai Liu, “Reversible writing/deleting of magnetic skyrmions through hydrogen adsorption/desorption“, Nature Communications, 13, 1350 (2022).

P. D. Murray, C. J. Jensen, A. Quintana, J.W. Zhang, X.X. Zhang, A. J. Grutter, B. J. Kirby, and Kai Liu, “Electrically Enhanced Exchange Bias via Solid State Magneto-Ionics”, ACS Applied Materials and Interfaces, 13, 38916−38922 (2021).

G. Chen, M. Robertson, M. Hoffman, C. Ophus, A. L. F. Cauduro, R. Lo Conte, H. F. Ding, R. Wiesendanger, S. Blügel, A. K. Schmid, and Kai Liu, “Observation of hydrogen-induced Dzyaloshinskii-Moriya interaction and reversible switching of magnetic chirality”, Physical Review X, 11, 021015 (2021).

J. Malloy, A. Quintana, C. J. Jensen, and Kai Liu, “Efficient and Robust Metallic Nanowire Foams for Deep Submicrometer Particulate Filtration”, Nano Letters, 21, 2968-2974 (2021).

E. C. Burks, D. A. Gilbert, P. D. Murray, C. Flores, T. E. Felter, S. Charnvanichborikarn, S. O. Kucheyev, J. Colvin, G. Yin and Kai Liu, “3D Nanomagnetism in Low Density Interconnected Nanowire Networks”, Nano Letters, 21, 716-722 (2021).

G. Chen, A. Mascaraque, H.Y. Jia, B. Zimmermann, M. Robertson, R. Lo Conte, M. Hoffmann, M.A.G. Barrio, H.F. Ding, R. Wiesendanger, E. Michel, S. Blügel, A. Schmid, and Kai Liu, “Large Dzyaloshinskii–Moriya interaction induced by chemisorbed oxygen on a ferromagnet surface”, Science Advances, 6, eaba4924 (2020).

Z. L. Wang, X. D. Xue, H. W. Lu, Y. X. He, Z. W. Lu, Z. J. Chen, Y. Yuan, N. Tang, C. A. Dreyer, L. Quigley, N. Curro, K. S. Lam, J. H. Walton, T. Y. Lin, A. Y. Louie, D. A. Gilbert, Kai Liu, K. W. Ferrara, and Y. P. Li, “Two-way magnetic resonance tuning and enhanced subtraction imaging for non-invasive and quantitative biological imaging”, Nature Nanotechnology, 15, 482-490 (2020).

P. D. Murray,  D. A. Gilbert,  A. J. Grutter,  B. J. Kirby,  D. Hernandez-Maldonado,  M. Varela, Z. E. Brubaker,  R. V. Chopdekar,  V. Taufour,  R. J. Zieve,  J. R. Jeffries,  E. Arenholz,  Y. Takamura, J. A. Borchers, and Kai Liu, “Interfacial-Redox-Induced Tuning of Superconductivity in YBa2Cu3O7-δ“, ACS Applied Materials & Interfaces, 12, 4741-4748 (2020).

H. X. Yang, G. Chen, A. A. C. Cotta, A. T. N’Diaye, S. A. Nikolaev, E. A. Soares, W. A. A. Macedo, Kai Liu, A. K. Schmid, A. Fert, and M. Chshiev, “Significant Dzyaloshinskii-Moriya Interaction at Graphene-Ferromagnet Interfaces due to Rashba-effect”, Nature Materials, 17, 605-609 (2018).

D. A. Gilbert, E. C. Burks, S. V. Ushakov, P. Abellan, I. Arslan, T. E. Felter, A. Navrotsky, and Kai Liu, “Tunable Low Density Palladium Nanowire Foams”, Chemistry of Materials, 29, 9814–9818 (2017).

W. J. Jiang, G. Chen, Kai Liu, J. D. Zang, S. G. E. te velthuis and A. Hoffmann, “Skyrmions in magnetic multilayers”, Physics Reports, 704, 1-49 (2017).

D. A. Gilbert, A. J. Grutter, E. Arenholz, Kai Liu, B. J. Kirby, J. A. Borchers, B. B. Maranville, “Structural and Magnetic Depth Profiles of Voltage-Controlled Magneto-Ionic Heterostructures Beyond the Interface Limit”, Nature Communications, 7, 12264 (2016).

D. A. Gilbert, J. Olamit, R. K. Dumas, B. J. Kirby, A. J. Grutter, B. B. Maranville, E. Arenholz, J. A. Borchers, and Kai Liu, “Controllable Positive Exchange Bias via Redox-Driven Oxygen Migration”, Nature Communications, 7, 11050 (2016).

D. A. Gilbert, B. B. Maranville, A. L. Balk, B. J. Kirby, P. Fischer, D. T. Pierce, J. Unguris, J. A. Borchers, and Kai Liu, “Realization of Ground State Artificial Skyrmion Lattices at Room Temperature”, Nature Communications, 6, 8462 (2015).

D. A. Gilbert, G. T. Zimanyi, R. K. Dumas, M. Winklhofer, A. Gomez, N. Eibagi, J. L. Vicent, and Kai Liu, “Quantitative Decoding of Interactions in Tunable Nanomagnet Arrays Using First Order Reversal Curves”, Scientific Reports, 4, 4204 (2014).