General Information
Name
Qing Liao
Gender
Male
Birth
27/02/1983, China
Citizenship
Chinese
Major
Physical Electronics
Email
[email protected]
Address
Department of Physics, Kansas State University,
116 Cardwell Hall Manhattan, KS 66506, USA
Education
09/2005-06/2009 Ph.D., Physical Electronics, School of Optoelectronic Science and
Engineering, Huazhong University of Science and Technology, Wuhan,
P. R. China
Advisor: Peixiang Lu
Dissertation Title: “Measurement of Phase of Ultrashort Pulses and
Electron Correlation in Nonsequential Double ionization”
09/2001-06/2005 B.Sc., Applied Physics, Department of Physics, Huazhong University of
Science and Technology, Wuhan, P. R. China
Work and Professional Experience
04/2012-03/2015 Postdoctoral Fellow, Department of Physics, Kansas State University,
USA
08/2009-12/2011 Postdoctoral Fellow, Wuhan National Laboratory for Optoelectronics,
Huazhong University of Science and Technology, China
(1) Above Threshold Ionization. By numerically solving the time-dependent Schrodinger
equation (TDSE), I studied the carrier-envelope phase (CEP) dependence of high-order
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above-threshold ionization of HeH2+ molecules and the interference of returning
photoelectron wave packets associated with the long and the short quantum paths. The
much larger left-right asymmetry of photoelectron yield of HeH2+ than that of atoms and
the extreme phase sensitivity of large-scale interference fringes were proposed as tools to
precisely measure CEP.
(2) Nonsequential Double Ionization. Extending TDSE to a correlated two-electron
model, I studied double ionization of HeH+ molecules and found that both nonsequential
double ionization (NSDI) and sequential double ionization (SDI) mechanisms induced
events exhibit asymmetric distribution in the two-electron momentum spectra, and they are
separated in the two-electron momentum distributions, due to the asymmetric charge
configuration of HeH+. The manipulating of the two-electron emission direction and yield
was demonstrated in NSDI of HeH+ using classical ensemble model.
I also explored the mechanism of NSDI at NIR wavelengths and low laser intensities:
multiphoton double ionization from doubly excited states induced by recollision, which
reasonably explains the recent experimental results. In addition, I found multiphoton Rabi
oscillation of double-electron in He atoms at UV wavelengths. The corresponding Rabi
frequency and period are identified by the two-electron energy spectra and by
time-resolved double ionization yield respectively. Rabi oscillation of two correlated
electrons are expected to be used in quantum coherent control.
(3) Attosecond Streaking Photoemission Time Delay. Recent two years, I have been
working in the group of Prof. Uwe Thumm on quantum-mechanical simulations of
attosecond streaking photoemission from condensed matter systems such as metal and
metal-metal systems. We have established a quantum-mechanical model, based on
strong-field approximation, which quantitatively reproduces measured relative streaking
time delays between photoemission from conduction band and core-levels of metal
surfaces and metal-metal surfaces in a series of attosecond streaking experiments. We have
systematically studied the influence of the screening of streaking fields, electron mean free
path, electron localization and XUV chirp on the attosecond streaking photoelectron
spectrum profile and time delays.
We are extending our model to attosecond time-resolved photoemission with
reconstruction of attosecond beating by interference of two-photon transitions (RABBITT)
technique on condensed matters. Also, we expect to extend our model to attosecond
time-resolved photoemission from more complex systems, such as nanospheres, nanowires
and other nanostructure targets.
Research Interests

Attosecond time-resolved photoemission from atoms and condensed matters

Electron correlations in strong-field double ionization

Nonlinear optical phenomena in atom-laser interactions

Ultrafast electronic dynamics in atoms and molecules driven by strong laser field
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Publications
[1] U. Thumm, Q. Liao, E. M. Bothschafter, F. Süβmann, M. F. Kling, and R. Kienberger,
Chapter XIII in: Handbook of Photonics, Volume 1 (Wiley, January 2015).
[2] Q. Liao and U. Thumm, “Initial-state, mean-free path, and skin-depth dependence of
attosecond time-resolved IR-streaked XUV photoemission from single-crystalline
magnesium,” Physical Review A 89, 033849 (2014).
[3] Q. Liao and U. Thumm, “Attosecond time-resolved photoelectron dispersion and
photoemission time delays,” Physical Review Letters 112, 023602 (2014).
[4] Q. Tang, Y. Zhou, C. Huang, Q. Liao, and P. Lu, “Correlated electron dynamics in
nonsequential double ionization of molecules by mid-infrared fields,” Optics
Express 20, 19580-19588 (2012).
[5] Y. Zhou, C. Huang, Q. Liao, and P. Lu, “Classical simulations including electron
correlations for sequential double ionization,” Physical Review Letters 109, 053004
(2012)
[6] C. Huang, Z. Li, Y. Zhou, Q. Tang, Q. Liao, and P. Lu, “Classical simulations of
electron emissions from H 2 + by circularly polarized laser pulses,” Optics Express, 20,
11700-11709 (2012).
[7] C. Huang, Y. Zhou, Q. Liao, and P. Lu, “Imaging molecular structures with
high-energy photoelectrons produced by extreme ultraviolet pulses,” JOSA B 29,
734-737 (2012).
[8] Q. Liao, Y. Zhou, C. Huang, and P. Lu, “Multiphoton Rabi oscillations of correlated
electrons in strong-field nonsequential double ionization,” New Journal of Physics
14, 013001 (2012).
[9] Y. Zhou, C. Huang, Q. Liao, W. Hong, and P. Lu, “Control the revisit time of the
electron wave packet,” Optics Letters 36, 2758-2760 (2011).
[10] A. Tong, Y. Zhou, C. Huang, Q. Liao, and P. Lu, “Enhanced ionization of
perpendicularly aligned H-2 in intense fileds,” Optics Communications 284,
2505-2508 (2011).
[11] A. Tong, Q. Liao, Y. Zhou, and P. Lu, “Internuclear-distance dependence of
nonsequential double ionization of H 2 in different alignments,” Acta Physica Sinica,
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60, 043301 (2011).
[12] C. Huang, Y. Zhou, A. Tong, Q. Liao, W. Hong, and P. Lu, “The effect of molecular
alignment on correlated electron dynamics in nonsequential double ionization,’’
Optics Express 19, 5627-5634 (2011).
[13] Y. Zhou, C. Huang, A. Tong, Q. Liao, and P. Lu, “Correlated electron dynamics in
nonsequential double ionization by orthogonal two-color pulses,” Optics Express 19,
2301-2308 (2011).
[14] Y. Zhou, Q. Liao, C. Huang, A. Tong, and P. Lu, “Electron Correlation in
Nonsequential Double Ionization of Helium by Two-Color Pulses,” Chinese Physics
Letters, 27 123201 (2010).
[15] Y. Zhou, Q. Liao, and P. Lu, “Asymmetric electron energy sharing in strong-field
double ionization of helium,” Physical Review A 82, 053402 (2010).
[16] Q. Liao and P. Lu, “Energy correlation in above-threshold nonsequential double
ionization at 800 nm,” Physical Review A, 82, 021403(R) (2010).
[17] Y. Zhou, Q. Liao, and P. Lu, “Complex sub-laser-cycle electron dynamics in
strong-field nonsequential triple ionization,” Optics Express 18, 16025-16034
(2010).
[18] C. Huang, Q. Liao, Y. Zhou, and P. Lu, “Role of Coulomb focusing on the electron
transverse momentum of above-threshold ionization,” Optics Express 18,
14293-14300 (2010).
[19] Tong A., Liao Q., Zhou Y., and P. Lu, “Internuclear-distance dependence of electron
correlation in nonsequential double ionization of H 2 ,” Optics Express 18, 9064-9070
(2010).
[20] Y. Zhou, Q. Liao, Q. Zhang, W. Hong and P. Lu, “Controlling nonsequential double
ionization via two-color few-cycle pulses,” Optics Express 18, 632-638 (2010).
[21] Q. Zhang, P. Lu, W. Hong, Q. Liao, and S. Wang, “Control of high-order harmonic
generation from molecules lacking inversion symmetry with a polarization gating
method,” Physical Review A 80, 033405 (2009).
[22] Q. Liao and P. Lu, “Manipulating nonsequential double ionization via alignment of
asymmetric molecules,” Optics Express 17, 15550-15557 (2009).
[23] Y. Zhou, Q. Liao, and P. Lu, “Mechanism for high-energy electrons in nonsequential
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double ionization below the recollision excitation threshold,” Physical Review A 80,
023412 (2009).
[24] Q. Zhang, P. Lan, W. Hong, Q. Liao, Z. Yang, and P. Lu, “The effect of controlling
laser field on broadband supercontinuum generation,” Acta Physica Sinica, 58,
4908-4913 (2009).
[25] Q. Zhang, P. Lu, W. Hong, Q. Liao, P. Lan, and X. Wang, ‘Enhanced high-order
harmonic generation via controlling ionization in spatially extended systems,”
Physical Review A 79, 053406 (2009).
[26] P. Lan, P. Lu, Q. Liao, Q. Zhang, and Z. Yang, “Phase-dependent photoionization in
the oversaturation regime,” Physical Review A 79, 033820 (2009).
[27] Y. Zhou, Q. Liao, P. Lan, and P. Lu, “Classical effects of carrier-envelope phase on
nonsequential double ionization,” Chinese Physical Letters 25, 3950-3953 (2008).
[28] Q. Liao, P. Lu, Q. Zhang, Z. Yang, and X. Wang, “Double ionization of HeH+
molecules in intense laser fields,” Optics Express 16,
17070-17075 (2008).
[29] Q. Liao, P. Lu, Q. Zhang, W. Hong, and Z. Yang, “Phase-dependent nonsequential
double ionization by few-cycle laser pulses,” Journal of Physics B 41, 125601
(2008).
[30] Q. Liao, P. Lu, P. Lan, Z. Yang, and Y. Li, “Method to precisely measure the phase of
few-cycle laser pulses,” Optics Express 16, 6455-6460 (2008).
[31] W. Hong, P. Lu, P. Lan, Z. Yang, Y. Li, and Q. Liao, “Broadband xuv supercontinuum
generaton via controlling quantum paths by a low-frequency field,” Physical Review
A 77, 033410 (2008).
[32] Q. Liao, P. Lu, P. Lan, W. Cao, and Y. Li, “Phase dependence of high-order
above-threshold ionization in asymmetric molecules,” Physical Review A 77,
013408 (2008).
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