1. Exploration of the mechanism of high-temperature superconductivity

(a) Using epitaxial intercalation method [Nature 348, 145 (1990)], the iodine atomic layer is inserted into the high-temperature superconductor for the first time, which proves that the interlayer interaction does not dominate high-temperature superconductivity in cuprates [Science 254, 1487 (1992)]; Furthermore, metallic behaviors of c-axis electrical transport properties of high-temperature superconductors inserted with iodine atoms does not support the mechanism of quantum tunneling superconductivity[Phys. Rev. Lett. 68, 530, (1992)].

(b) By measuring the transport properties of single crystal K3C60 [Science 256, 1190 (1992)], the three-dimensional quantum fluctuation in superconductors has been verified for the first time [Nature 361, 54 (1993)].

(c) Using microwave near-field microscope, the phase boundary of electronic states is observed in the strongly correlated system, which supports Kivelson's "sematic phase theory" [Nature 406, 704, (2000)]

(d) Proposed a new scattering mechanism affecting electron transport under electromagnetic field for the first time. This solves the long-standing problem of Drude-Sommerfeld model, which cannot determine the quantum relaxation time due to contradiction between experimental data and Model, and successfully extracts the quantum relaxation time of conducting electrons from the width of plasma resonance peak [Natl. Sci. Rev. 8, 4 (2021)]. This method laid a foundation for further investigation of high-Tc superconductivity.

2. Sciences and applications of Material Genome Engineering

(a) Using mask method and low-temperature diffusion method, multiple materials or binary and ternary phase diagrams are grown on one substrate for the first time. This could apply to the high-throughput screening and discovery of high-temperature superconductivity, giant magnetoresistance, fluorescence, dielectric, magnetic and other materials [Science 268, 1738 (1995); Science 270, 273 (1995); Science 279, 1712 (1998)].

(b) Invented a high-resolution microwave near-field microscope which can quantitatively measure the dielectric properties of materials and realize non-contact quantitative characterization of material chips [Science 276, 2004 (1997)].

(c) Taking advantages of white light source and energy dispersive surface detection, we overcome the shortcomings of ordinary surface detector diffraction technology and multi-point energy dispersive diffraction technology. This improves the characterization efficiency of structure and composition by four orders of magnitude (~ 42000 times) for the first time [Accepted in Engineering (2022)].

Publications

[1] Peng Zhang, Haoqi Tang, Chuanchuan Gu, Hong Wang, Guangfu Luo, Yalin Lu and X.-D. Xiang, “A direct measurement method of quantum relaxation time” National Science Review 8, nwaa242, (2021).

[2] Xiaoping Wang, Weiwei Dong, Peng Zhang, Haoqi Tang, Lanting Zhang, Tieying Yang, Peng Liu,

Hong Wang, X.-D. Xiang, “High-Throughput Powder Diffraction Using White X-Ray Beam and a Simulated Energy-Dispersive Array Detector” Engineering, accepted, (2022).

[3] X.-D. Xiang, Xiaodong Sun, Gabriel Briceno, Yulin Lou, Kai-An Wang, Hauyee Chang, WilliamGregory Wallace-Freedman, Sung-Wei Chen, Peter G. Schultz, “A Combinatorial Approach to Materials Discovery” Science 268, 1738 (1995).

[4] Yalin Lu, Tao Wei, Frederick Duewer, Yanqing Lu, Nai-Ben Ming, P.G. Schultz, and X.-D. Xiang, “Nondestructive Imaging of Dielectric Constant Profiles and Ferroelectric Domains with a Scanning Tip Microwave Near-Field Microscope” Science 276, 2004 (1997).

[5] X.-D. Xiang, J.G. Hou, W.A. Vareka, R. Mostovoy, A. Zettl, Marvin L. Cohen, “Synthesis and Electronic Transport of Single Crystal K3C60” Science 256, 1190 (1992).

[6] Gabriel Briceno, Hauyee Chang, Xiaodong Sun, Peter G. Schultz, and X.-D. Xiang, “Discovery of a Class of Cobalt Oxide Magnetoresistance Materials Using Combinatorial Synthesis” Science 270, 273 (1995).

[7] X.-D. Xiang, J.G. Hou, Vincent H. Crespi, A. Zettl, and Marvin L. Cohen, “3-Dimensional Superconducting Fluctuation Conductivity in Single Crystal K3C60 and Rb3C60” Nature 361, 54 (1993).

[8] X.-D. Xiang, W.A. Vareka, A. Zettl, J.L. Corkill, T. W. Babee III, Marvin L. Cohen, N. Kijima and R. Gronsky, “Tuning High-Tc superconductors via Multi-stage Intercalation” Science 254,1487 (1992).

[9] Young K. Yoo, Fred Duewer, Haitao Yang, Dong Yi, and X.-D. Xiang, “Room Temperature Electronic Phase Transitions Observed in the Continuous Phase-Diagrams of Perovskite Manganites” Nature 406, 704, (2000).

[10] X.-D. Xiang, S. Mckernan, W. A. Vareka, A. Zettl, J. L. Conkill, T. W. Barbee III, and Marvin L. Cohen, “Iodine Intercalation of a High-temperature Superconducting Oxide” Nature 348, 145 (1990).

[11] Jingsong Wang, Young Yoo, Chen Gao, Ichiro Takeuchi, Xiaodong Sun, X-D. Xiang, Peter G. Schultz, “Discovery of a Novel Blue Photoluminescent Materials Using Combinatorial Libraries” Science 279, 1712 (1998).

[12] Xiang XD, Brill JW. “Frequency-Dependence of Elastic Anomalies in Charge-Density-Wave Conductors” Physical Review Letters 63, 1853-1856 (1989).

[13] Xiang XD, Vareka WA, Zettl A, Corkill JL, Cohen ML, Kijima N, Gronsky R. “Metallization of the Resistivity Tensor in Bi2Sr2CaCu2OX Through Epitaxial Intercalation” Physical Review Letters 68, 530-533(1992).