Subcycle Transient
Scanning Tunneling Spectroscopy with Visualization of Enhanced Terahertz
Near Field
Shoji Yoshida
Hideki Hirori
Takehiro Tachizaki
Katsumasa Yoshioka
Yusuke Arashida
Zi-Han Wang
Yasuyuki Sanari
Osamu Takeuchi
Yoshihiko Kanemitsu
Hidemi Shigekawa
10.1021/acsphotonics.9b00266.s001
https://acs.figshare.com/articles/journal_contribution/Subcycle_Transient_Scanning_Tunneling_Spectroscopy_with_Visualization_of_Enhanced_Terahertz_Near_Field/8159090
The recent development
of optical technology has enabled the practical
use of a carrier-envelope phase-controlled monocycle electric field
in the terahertz (THz) regime. By combining this technique with metal
nanostructures such as nanotips, which induce near-field enhancement,
the development of novel applications is anticipated. In particular,
THz scanning tunneling microscopy (THz-STM) is a promising technique
for probing ultrafast dynamics with the spatial resolution of STM.
However, the modulation of the THz waveform is generally accompanied
by an enhancement of the electric field, which is unknown in actual
measurement environments. Here, we present a method enabling direct
evaluation of the enhanced near field in the tunnel junction in THz-STM
in the femtosecond range, which is essential for the use of the THz
near field. In the tunneling regime, it was also demonstrated that
the transient electronic state excited by an optical pulse can be
evaluated using the THz-STM, and the ultrafast carrier dynamics in
2H-MoTe<sub>2</sub> excited by an optical pulse was reproducibly probed.
2019-05-16 00:00:00
Enhanced Terahertz
femtosecond range
carrier-envelope phase-controlled monocycle
2 H-MoTe 2
metal nanostructures
pulse
Subcycle Transient Scanning Tunneling Spectroscopy
THz scanning tunneling microscopy
measurement environments
ultrafast dynamics
tunnel junction
technique
near-field enhancement
STM
ultrafast carrier dynamics
THz waveform
tunneling regime
novel applications
THz-STM