Research

Quantum dynamics of excitons and spin-valley optoelectronics 

Our group is interested in investigating the exciton and spin-valley dynamics in low-dimensional materials, such as van der Waals (vdW) two-dimensional (2D) materials.  Using scanning microscopy systems combined with ultrafast lasers, we can perform spatially-resolved (~ 1 µm) and temporally-resolved (~ 100 fs) photoresponse in these materials. Recent works include optoelectronic manipulation of valley-locked spin-photocurrents [1] and exciton dynamics in 2D TMDs (transition metal dichalcogenides) vdW materials [2-4].

[1] Nature Nanotechnology 13, 910-914 (2018) (pdf).
[2] Nature Communications 9, 351 (2018) (pdf).
[3] Nature Communications 7, 13569 (2016) (pdf).
[4] Nature Communications 710768 (2016) (pdf).

 

Quantum spintronics and plasmonics

We explore femtosecond laser-controlled spintronic and plasmonic applications using topological insulators or plasmonic metamaterials. Injection of the time-delayed optical pulses selectively excite the spin-polarized electrons, and thus may lead us to develop new optically-controlled ultrafast spintronic devices. Emphasis is made on the electrical and optical manipulation of spin and plasmon by integrating two or more dissimilar materials [1-4].

[1] ACS Photonics 5(8), 3347-3352 (2018) (pdf).
[2] Nano Letters 18, 734 (2018) (pdf).
[3] Nature Communications 6, 8814 (2015) (pdf).
[4] Advanced Materials 28, 1495 (2016) (pdf).