Real-space coherent manipulation of electrons in a single tunnel junction by single-cycle terahertz electric fields

Abstract

The ultrafast coherent manipulation of electrons using waveform-controlled laser pulses 1-9 is a key issue in the development of modern electronics 10,11. Developing such an approach for a tunnel junction will provide a new platform for governing ultrafast currents on an ever smaller scale, which will be indispensable for the advancement of next-generation quantum nanocircuits 12-15 and plasmonic devices 16-18. Here, we demonstrate that carrier-envelope phase controlled single-cycle terahertz electric fields can coherently drive electron tunnelling either from a nanotip to a sample or vice versa. Spatially confined electric fields of more than 10 V/nm strongly modulate the potential barrier at a nanogap in a scanning tunnelling microscope (STM) within a sub-picosecond time scale and can steer a huge number of electrons in an extremely nonlinear regime, which is not possible using a conventional STM. Our results are expected to pave the way for the future development of nanoscale science and technologies.

Tipping solutions: emerging 3D nano-fabrication/ -imaging technologies

“…Interpretation of data from the near-field requires further knowledge of probe-surface interaction, phase information of the reflected/transmitted light from sub-wavelength structures to reveal complex peculiarities of light-matter interactions at the nanoscale [118][119][120][121][122][123]. Recently, electron tunneling control by a single-cycle terahertz pulse illuminated onto a tip of scanning tunneling electron microscope (STEM) needle was demonstrated at 10 V/nm fields [124]. STEM reached an atomic precision in surface probing and spectroscopic characterization, including that for water [125].…”

Terahertz dynamics of electron–vibron coupling in single molecules with tunable electrostatic potential

“…To overcome this problem, we adopted the time-domain THz autocorrelation measurements, [16][17][18][19] as shown in Fig. 1c.…”

Carrier-envelope phase effects in graphene

“…This is well-suited for the study of electronhole pair production in graphene. As the THz pulse duration can easily be reduced down to few optical cycles (sub-picoseconds duration), the CEP of the pulse needs to be characterized and tuned [28,29]. Studies of CEP measurement have been performed in atomic, molecular and optical physics mostly using few-cycle near-infrared laser pulses (at λ = 800 nm).…”