# Xuan Gao

#### Associate Professor

#### Concentrations

Experimental condensed matter physics; Nanoscale electronic transport; Two-dimensional electrons in semiconductor, oxide hetero-interfaces or graphene-like atomically thin crystals; Topological insulators; Electron correlation effects in transport; Thermoelectric and photovoltaic energy conversion; Nano-electronics and sensors.

#### Interests

Our lab focuses on the understanding and exploration of how quantum nature of matter, low dimensionality, confinement, electronic structure topology, symmetry, and electron-electron correlation effects etc give rise to new electrical, thermal, magnetic and optical phenomena or properties in nanoscale/low-dimensional solid state systems. The material systems we study span semiconductors, semimetals, oxides, and even organic compounds, often in the form of nanostructures. The techniques we use in research include but not limited to vapor deposition growth of materials, nano-device fabrication, electron transport, magneto-transport, capacitance spectroscopy, thermal transport, scanning photoconductivity microscopy characterizations, and various composition/ structural analysis methods. We are also interested in applying our results to real life applications (e.g. electronics, optoelectronics, energy conversion/harvesting).

We are looking for talented and motivated students (both undergraduates and graduates) and postdocs to help solve important issues in condensed matter physics and nanoscience. If you are interested in current research opportunities in Gao’s group, please contact Prof. Xuan Gao.

#### Publications

S. Sucharitakul, N. J. Goble, U. R. Kumar, R. Sankar, Z. A. Bogorad, F. C. Chou, Y.T. Chen, X. P. A. Gao, “Intrinsic Electron Mobility Exceeding 1000 cm2/(Vs) in Multilayer InSe FETs”, *Nano Letters*, 15 (6), 3815-3819 (2015).

T. Q. Ngo, N. J. Goble, A. Posadas, K. J. Kormondy, S. Lu, M. D. McDaniel, D. J. Smith, X. P. A. Gao, A. A. Demkov, and J. G. Ekerdt,”Quasi-two-dimensional Electron Gas at the Interface of gamma-Al2O3/SrTiO3 Heterostructures Grown by Atomic Layer Deposition”, *Journal of Applied Physics*, 118, 115303 (2015).

N.J. Goble, J.D. Watson, M.J. Manfra and X. P.A. Gao, “Impact of short range scattering on the 2D metallic transport in a correlated 2D Hole System”, *Physical Review B*, **90**, 035310 (2014).

Z.H. Wang, R. L.J. Qiu, C.H. Lee, Z.D. Zhang, X. P.A. Gao, “Ambipolar Surface Conduction in Ternary Topological Insulator Bi_{2}(Te_{1-x}Se_{x})_{3} Nanoribbons”, *ACS Nano* **7**, 2126-2131 (2013).

Y. Tian, M. R. Sakr, J. M. Kinder, D. Liang, R. L.J. Qiu, M. J. MacDonald, H.-J. Gao and X. P.A. Gao, “One-dimensional quantum confinement modulated thermoelectric properties in InAs nanowires”, *Nano Letters* **12**, 6492-6497 (2012).

R. L.J. Qiu, X. P.A. Gao, L. N. Pfeiffer, K. W. West, “Connecting the reentrant insulating phase and the zero field metal-insulator transition in a 2D hole system”, *Physical Review Letters* **108**, 106404 (2012).

D. Liang, X. P.A. Gao, “Strong tuning of spin orbit interaction in an InAs nanowire by surrounding gate”, *Nano Letters***12** (6), 3263-3267 (2012).

H. Tang, D. Liang, R. L.J. Qiu and X. P.A. Gao, “Two-Dimensional Transport Induced Linear Magneto-Resistance in Topological Insulator Bi2Se3 Nanoribbons”, *ACS Nano* **5**, 7510-7516 (2011)

B. Spivak, S. V. Kravchenko, S. A. Kivelson, and X. P. A. Gao, “Transport in Strongly Correlated Two-Dimensional Electron Fluids”, *Reviews of Modern Physics* **82**, 1743 (2010).

X. P. A. Gao, G.F. Zheng and C.M. Lieber, “Subthreshold Regime has the Optimal Sensitivity for Nanowire FET Biosensors”, *Nano Letters* **10**, 547 (2010).

J. Du, D. Liang, H. Tang and X.P.A. Gao, “InAs Nanowire Transistor as Gas Sensor and the Response Mechanism”,*Nano Letters* **9**, 4348 (2009).

## Contact

xuan.gao@case.edu

216.368.4031

Rockefeller Building 104C

## Education

B.S., South China University of Technology (1998)

Ph.D., Columbia University (2003)