Academic Profile

Academic Profile

Asst Prof Loh Zhi Heng

Assistant Professor
Division of Chemistry & Biological Chemistry
School of Physical & Mathematical Sciences
College of Science

Phone: (+65)65921655
Office: SPMS-CBC-01-19A

  • PhD (Chemistry) University of California, Berkeley 2008
  • S.B. (Chem) Massachusetts Institute of Technology 2003
Research Interests
The central theme of our experimental research program is the study of coherent electron and nuclear dynamics in molecules and nanomaterials. Coherent electron motion and the ensuing quantum dynamics set forth by either optical excitation or nonresonant strong-field ionization with few-cycle laser pulses will be probed with attosecond to femtosecond time resolution. This proposed work builds upon my previous work, in which coherent electron motion in Kr+ ions that accompanies the formation of a spin-orbit wave packet is observed (Nature, 2010).

The main experimental techniques that are employed include attosecond time-resolved core-level transient absorption and transient photoelectron spectroscopies, in which soft x-ray pulses produced in a tabletop setup by high-order harmonic generation are used as probe. These soft x-ray studies are complimented with optical pump-probe measurements employing few-cycle (~5 fs) laser pulses. The ultimate goal of our studies is to exploit quantum coherences to enhance the performance of nanoelectronics and artificial light harvesting systems.
Research Grant
  • Academic Research Fund Tier 1 (2017-) [by MOE]
  • Academic Research Fund Tier 2 (2015-)
Current Projects
  • Attosecond X-ray Metrology of Valence Electron Dynamics in Nanoscale Functional Materials
  • Coherent Quantum Dynamics Probed by Femtosecond Soft X-Ray Spectroscopy
  • Coupled Electronic-Vibrational Quantum Coherences Probed by Femtosecond Tabletop XUV and X-Ray Free-Electron Laser Sources
  • Development of a Tabletop High-Repetition-Rate Femtosecond Extreme Ultraviolet Light Source for Ultrafast Spectromicroscopy
  • Femtosecond Electron and Ion Dynamics of Ionized Biomolecules in Solution
  • NAP Grant (Seed Funding) - Real Time Observation of Attosecond Quantum Dynamics
Selected Publications
  • Zhaogang Nie, Run Long, Linfeng Sun, Chung-Che Huang, Jun Zhang, Qihua Xiong, Daniel W. Hewak, Zexiang Shen, Oleg V. Prezhdo, Zhi-Heng Loh. (2014). Ultrafast Carrier Thermalization and Cooling Dynamics in Few-Layer MoS2. ACS Nano, 8, 10931-10940.
  • Stephen R. Leone, C. William McCurdy, Joachim Burgdörfer, Lorenz S. Cederbaum, Zenghu Chang, Nirit Dudovich, Johannes Feist, Chris H. Greene, Misha Ivanov, Reinhard Kienberger, Ursula Keller, Matthias F. Kling, Zhi-Heng Loh, Thomas Pfeifer, Adrian N. Pfeiffer, Robin Santra, Kenneth Schafer, Albert Stolow, Uwe Thumm and Marc J. J. Vrakking. (2014). What Will It Take to Observe Processes in ‘Real Time’?. Nature Photonics, 8, 162-166.
  • Zhaogang Nie, Run Long, Jialin Li, Yi Ying Zheng, Oleg V. Prezhdo, and Zhi-Heng Loh. (2013). Selective Excitation of Atomic-Scale Dynamics by Coherent Exciton Motion in the Non-Born−Oppenheimer Regime. Journal of Physical Chemistry Letters, 4, 4260−4266.
  • Jialin Li , Zhaogang Nie , Yi Ying Zheng , Shuo Dong , and Zhi-Heng Loh. (2013). Elementary Electron and Ion Dynamics in Ionized Liquid Water. Journal of Physical Chemistry Letters, 4, 3698-3703.
  • Zhi-Heng Loh, Stephen R. Leone. (2013). Capturing Ultrafast Quantum Dynamics with Femtosecond and Attosecond X‑ray Core-Level Absorption Spectroscopy (Invited Perspectives Article). Journal of Physical Chemistry Letters, 4, 292-302.

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