Polaron dynamics in two-dimensional photon-echo spectroscopy of molecular rings

Thanh Duc Huynh, Kewei Sun, Maxim Gelin, and Yang Zhao, Journal of Chemical Physics (2013)

Dynamics of a two-level system under the influence of a spin bath and a boson bath simultaneously

Ning Wu and Yang Zhao, Journal of Chemical Physics (2013)

Entanglement dynamics of two qubits coupled individually to Ohmic bath

Liwei Duan, Hui Wang, Qinghu Chen, and Yang Zhao, Journal of Chemical Physics (2013)

A variational surface-hopping algorithm for the sub-Ohmic spin-boson model

Yao Yao and Yang Zhao, Journal of Chemical Physics (2013)

Role of Formation of Statistical Aggregates in Chlorophyll Fluorescence Concentration Quenching

Wujin Shi, James Barber, and Yang Zhao, Journal of Physical Chemistry B (2013)

Environmental Effects on Electronic Transitions of the FMO Complex

J.K. Gao, W.J. Shi, X.Q. Wang, H. Hirao, and Y. Zhao, Journal of Physical Chemistry B (2013)

Excitonic energy transfer in light-harvesting complexes in purple bacteria

J. Ye, K.W. Sun, Y. Zhao, Y. Yu, C. Lee, and J.S. Cao, Journal of Chemical Physics (2012)

Resonant Energy Transfer via Off-Diagonal Coupling

N. Wu, K.W. Sun, Z. Chang, and Y. Zhao, Journal of Chemical Physics 136 , 124513 (2012)

Long-range Energy Propagation in Nano-Engineered LH2 Antenna Arrays

G. Yang, N. Wu, T. Chen, K.W. Sun, and Y. Zhao, J. Phys. Chem. C 116 , 3747 (2012)

Micromagnetics for Nanoarrays

B. Yang and Y. Zhao, J. Appl. Phys. 110 , 103908 (2011)

Electrical Percolation in Nanocomposites

X. Zeng, X. Xu, P.M. Shenai, E. Kovalev, C. Baudot, N. Mathews, and Y. Zhao, J. Phys. Chem. C 115 , 21685 (2011)

Appeared in the Shaul Mukamel Festschrift...

Improved results have been obtained on the temperature dependence of transport properties of an extended Holstein molecular crystal model incorporating simultaneous diagonal and off-diagonal exciton-phonon coupling. The Hamiltonian is partially diagonalized by a canonical transformation and the optimal coefficients for the canonical transformation are determined in a self-consistent manner. Calculated transport properties exhibit substantial corrections on those obtained previously by Munn and Silbey for a wide range of temperatures thanks to the numerically exact evaluation and added momentum-dependence of the transformation matrix. Results of the diffusion coefficient in the moderate and weak coupling regime show distinct band-like and hopping-like transport features as a function of temperature.

D.M. Chen, J. Ye, H.J. Zhang, and Y. Zhao, J. Phys. Chem. B 115 , 5312 (2011).

Success of Dr Zhao's CRP team in the news* !

Media reports on the 2010 award (including those from USA Today and Business Times)

* Note: The full CRP team is composed of Drs Y. Zhao, J.L. Wang, H.S. Tan, A. Grimsdale, C. Xue, T.C. Sum & H.D. Sun.

Topics that also interest us ...

Aromatic molecules can effectively exfoliate graphite into graphene monolayers, and the resulting graphene monolayers sandwiched by the aromatic molecules exhibit a pronounced Raman G-band splitting, similar to that observed in single-walled carbon nanotubes. Raman measurements and calculations based on the force-constant model demonstrate that the absorbed aromatic molecules are responsible for the G-band splitting by removing the energy degeneracy of in-plane longitudinal and transverse optical phonons at the Gamma point.

 

Xiaochen Dong, Yumeng Shi, Yang Zhao et al., Phys. Rev. Lett. 102, 135501 (2009).

 

Miniaturization of electronic and mechanical devices over the past century has brought immeasurable impact onto human lives. Commercial microelectromechanical systems have reached micron scales, and bona fide molecular apparatuses began to emerge setting the stage for upcoming integrated nanoelectromechanics. Dr. Zhao and coworkers systematically investigate carbon-nanotube-based oscillators, bearings and rotators via molecular dynamics simulation in order to establish their optimal operating conditions and to facilitate function-oriented designs. In addition, particular attention is paid to utilization of nanomachinery devices as nanolabs to study energy exchanges among various degrees of freedom, ergodicity on energy surfaces, and equipartition as systems relax, and to test fundamental hypotheses of thermodynamics and statistical mechanics.

 

Y. Zhao, C.C. Ma, G.H. Chen, Q. Jiang, Phys. Rev. Lett. 91, 175504 (2003).


 

The advent of ultrafast femtosecond laser spectroscopy brings about intense research interest in relaxation dynamics of photo-excited states in liquids and solids. Newly-arrived technological capabilities to control femtosecond pulse durations and down-to-one-hertz bandwidth resolutions provide novel probes on vibrational dynamics and excitation relaxation. Dr. Zhao and coworkers formulate time-dependent polaronic wave functions that facilitate microscopic modelling of photo-generated excitation relaxation and realistic computation of various third-order optical response functions, and help to achieve a satisfactory comparison between theory and experiment.


 

Carbon nanotubes are attractive candidates for a variety of applications thanks to their remarkable physical, chemical, and mechanical properties. Optical absorption and fluorescence spectroscopy measurements have become an important tool for structure-based characterization and DNA-assisted manipulation of carbon nanotubes. Dr. Zhao and coworkers establish visual, intuitive connections between optical absorption line shapes and their underlying nanotube structures, which are scrutinized by more sophisticated semi-empirical and DFT calculations.

 

We are searching for PhD students and research fellows with trainings in Materials Science, Physics, or Chemistry. CVs should be sent via postal mail or email to Dr. Zhao.

Zhao Yang © copyright Feburary 2008, School of Materials Sci. & Eng., Nanyang Technological University