His research interest is using ultrafast pump-probe spectroscopy to interrogate and control quantum materials (strongly correlated materials) and artificial materials (metamaterials and plasmonics) through light-matter interaction in the linear and nonlinear regime. In particular, non-equilibrium dynamics is initiated and subsequently monitored by intense pump pulses and relatively weaker probe pulses, respectively, that exploit diverse spectroscopic methods, ranging from time-domain terahertz (THz) spectroscopy, multi-THz spectroscopy to X-ray scattering. Exotic transient/metastable states in quantum materials or intriguing electromagnetic response in artificial materials can, therefore, be effectively identified by cautious selection of pump and probe beam that carries information of elementary excitations at their fundamental time scales (10-15 s to 10-12 s).

• Ultrafast pump-probe spectroscopy: time-domain THz/multi-THz spectroscopy; time-resolved X-ray scattering
• Non-equilibrium dynamics and photo-induced phase transition in quantum materials
• Terahertz plasmonics and metamaterials in the linear and non-linear regime

• *K. A. Cremin, *J. Zhang, C.C. Homes, Genda D. Gu, Zhiyuan Sun, Michael M. Fogler, Andrew J. Millis, D.N. Basov and R.D. Averitt, Photo-enhanced metastable c-axis electrodynamics in stripe ordered cuprate La_1.885Ba_0.115CuO₄. (2019) (arXiv 1901.10037) (*equal contribution)
• J. Zhang, X. Tan, M. Liu, S. W. Teitelbaum, K. W. Post, F. Jin, K. A. Nelson, D. N. Basov, W. Wu and R. D. Averitt, Cooperative photoinduced metastable phase control in strained manganite films. Nature Materials 15, 956-960 (2016).
• J. Zhang and R. D. Averitt, Dynamics and control in complex transition metal oxides. Annual Review of Materials Research, 44, 19-43 (2014).
• J. Zhang, J. Yong, I. Takeuchi, R. L. Greene and R. D. Averitt, Ultrafast terahertz spectroscopy study of Kondo insulating thin film SmB6: evidence for an emergent surface state. Physical Review B, 97, 155119 (2018)
• K. Fan, J. Zhang, X. Liu, G. F. Zhang, R. D. Averitt, W. J. Padilla, Phototunable dielectric Huygens’ metasurfaces, Advanced Materials, 1800278 (2018)
• *J. Zhang, *X. Zhao, K. Fan, X. Wang, G. F. Zhang, K. Geng, X. Zhang, R. D. Averitt, Terahertz radiation-induced sub-cycle field electron emission across a split-gap dipole antenna. Applied Physics Letters, 107, 231101 (2015). (*equal contribution)
• M. K. Liu, B. Pardo, J. Zhang, M. M. Qazilbash, S. J. Yun, Z. Fei, J.-H. Shin, H.-T. Kim, D. N. Basov, and R. D. Averitt, Photoinduced phase transitions by time-resolved far-infrared spectroscopy in V₂O₃. Physical Review Letters 107, 066403 (2011).

Full Publication List [HKUST Scholarly Publications]