Condensed Matter Physics - Experimental
Biomedical-Physical Sciences Bldg.
567 Wilson Rd., Room 4223
B130 Biomedical-Physical Sciences Bldg.
X. Ke, J. Peng, D. J. Singh, T. Hong, W. Tian, C. R. Dela Cruz, and Z. Q. Mao, "Emergent electronic and magnetic states in Ca3Ru2O7 induced by Ti doping", Phys. Rev. B 84, 201102 (R) (2011).
X. Ke, T. Hong, J. Peng, S. E. Nagler, G. E. Granroth, M. D. Lumsden, and Z. Q. Mao, "Spin wave excitation in the antiferromagnetic bilayer ruthenate Ca3Ru2O7", Phys. Rev. B, 84, 014422 (2011).
X. Ke, P. P. Zhang, S. Baek, J. Zarestky, W. Tian, and C. B. Eom, "Magnetic Structure of Multiferroic BiFeO3 Film with Controllable Ferroelectric Domains", Phys. Rev. B 82, 134448 (2010).
J. H. Lee, L. Fang*, E. Vlahos*, X. Ke*, Y. W. Jung, L. Fitting Kourkoutis, J.W. Kim, P. Ryan, T. Heeg, M. Roeckerath, V. Goian, M. Bernhagen, R. Uecker, C. Hammel, K. M. Rabe, S. Kamba, J. Schubert, J. W. Freeland, D. A. Muller, C. J. Fennie, P. Schiffer, V. Gopalan, E. Johnston-Halperin, and D. G. Schlom, "A strong ferroelectric ferromagnet created via spin-phonon coupling", Nature 466, 954 (2010).
P. E. Lammert, X. Ke, J. Li, C. Nisoli, D. Garand, V. H. Crespi, and P. Schiffer, "Direct entropy determination and application to artificial spin ice", Nature Physics 6, 786 (2010).
X. Ke, J. Li, C. Nisoli, Paul E. Lammert, W. McConville, R. F. Wang, V. H. Crespi, and P. Schiffer, "Energy minimization and AC demagnetization in a nanomagnet array", Phys. Rev. Lett. 101, 037205 (2008).
X. Ke, R. S. Freitas, B. G. Ueland, G. C. Lau, M. L. Dahlberg, R. J. Cava, R. Moessner, and P. Schiffer, "Non-monotonic zero point entropy in diluted spin ice", Phys. Rev. Lett. 99, 137203 (2007).
Professional Activities & Interests / Biographical Information
neutron scattering science, complex oxide materials, heterostructures, spintronics, magnetic nanostructures
Our research focus is to explore emergent phenomena in strongly correlated materials and complex oxide heterostructures, and to understand the underlying mechanisms.
Strongly correlated materials refer to a wide class of materials where the electron-electron Coulomb interaction is large and plays a key role in determining the materials properties. For strongly correlated materials, the interplay among spin, charge and lattice degrees of freedom often lead to exotic phases, such as high Tc superconductor, multiferroics, Mott insulators, etc. On the other hand, by growing different types of complex oxide materials on substrates to form so-call heterostructures, these oxide heterostructures can behave drastically different from bulk counterparts, largely due to the local structural distortions imposed by the epitaxial strain, the interfacial electronic, lattice and orbital reconstructions. This leads to in a variety of remarkable phenomena emerging in oxide heterostructures, such as 2D electron gas, induced superconducting interface, magnetoelectric coupling, etc. Due to the multifunctionality and tunablitity, correlated oxide heterostructures provide an opportunity to study the intriguing physics, design new materials, and may lead to innovative applications.
We will study materials properties by combining various neutron scattering techniques, including neutron diffraction, inelastic neutron scattering, and polarized neutron reflectivity, together with bulk electronic and thermo transport measurements. Specifically, we will investigate materials nuclear and magnetic structure, magnetic excitation, interfacial spin structure, and electronic and thermo transport properties.