- Address: Physics
Colorado School of Mines
Golden, CO 80401
- Colorado School of Mines
Ph.D. Applied Physics, 2012-present
Advisor: Mark T. Lusk
- Shandong University
B.S. Theoretical Physics, 2008-2012
Advisor: Mingwen Zhao
- Computer: Mathematica, Fortran
- Software: DMol3, OCTOPUS, Q-Chem, SIESTA
- Research Experience
Besides working with Prof. Mark T. Lusk, who is my advisor, I also worked with other theoretical physicists, Prof. Simone Montangero and Prof. Lincoln D. Carr and experimental chemist, Prof. Alan Sellinger.
- Teaching Experience
I have worked as teaching assistant for graduate courses such as Classical Mechanics, Quantum Mechanics, Electromagnetic Theory, Mathematical Statics and Materials Thermodynamics, and undergraduate courses such as Quantum Mechanics and Electromagnetics.
- 1. Excitonic Solar Cells
The observation of long-lived coherent exciton transfer during photosynthesis is our motivation for excitonic solar cells. In excitonic solar cells, the energy is transferred to charge separation interfaces in the form of exciton, an electron-hole pair, after the absorption of photon at the light-active components. So that an efficient and robust excitonic energy transfer is necessary. We explore strategies for designing systems in which excitonic energy is transferred with high efficiency.
- 2. Exciton-Based Quantum Information
Historically exciton could serve as quantum bit based on its absence or presence. On the other hand, orbital angular momentum of photon has made photon-based quantum information far more compelling. So that a good understanding of orbital angular momentum of exciton is necessary and we seek its actual applications in quantum infromation.
- 3. Exciton with Prescribed Shape, Speed and Direction
For 1-D molecule chain, we have demonstrated that the exciton wave packet induced by a well-engineered laser pulse could transfer with prescribed shape and speed. I am interested in producing exciton wave packet by engineered laser pulses to transferring with prescribed shape, speed and direction in 2-D molecule sheet.
- 4. New Formulation of Time-Domain Density Functional Theory (TD-DFT)
Conventional Kohn-Sham formulation of TD-DFT has been sufferring the issue that no full Rabi oscillation is available from it. This has been claimed to be caused by the lack of memory in current available exchange-correlation functionals. However we found that this is actually caused by the restriction of number of Kohn-Sham orbitals and their occupations. Our new formulation of TD-DFT released such restrictions and sucessfully generated full Rabi oscillation. Further development and tests are necessary.
- 1. X. Zang and M. T. Lusk, Designing Small Silicon Quantum Dots with Low Reorganization, Physical Review B 92 035426 10.1103/PhysRevB.92.035426 (2015)
- 2. R. T. Anderson, X. Zang, R. Fernando, M. J. Dzara, C. Ngo, M. Sharps, R. Pinals, S. Pylypenko, M. T. Lusk, and A. Sellinger, Direct Conversion of Hydride- to Siloxane-Terminated Silicon Quantum Dots, The Journal of Physical Chemistry C 120 25822-25831 10.1021/acs.jpcc.6b07930 (2016)
- 3. X. Zang, S. Montangero, L. D. Carr, and M. T. Lusk, Engineering and Manipulating Exciton Wave Packets, Physical Review B 95 195423 10.1103/PhysRevB.95.195423 (2017)
- 4. X. Zang and M. T. Lusk, Twisted Molecular Excitons as Mediators for Changing the Angular Momentum of Light, Physical Review A 96 013819 10.1103/PhysRevA.96.013819 (2017)
- 5. X. Zang and M. T. Lusk, Angular Momentum Transport with Twisted Exciton Wave Packets, arXiv 1706.10167 Physical Review B in review (2017)
- 6. X. Zang and M. T. Lusk, Rabi Oscillation in Real-Time Time-Dependent Density Functional Theory, in preparation (2017)
- 7. X. Zang and M. T. Lusk, Designing Silicon Quantum Dots Assemblies with Large Excitonic Coupling, in preparation (2017)