2026-10-14T23:24:09Z https://www.scidb.cn/oai

10.57760/sciencedb.27400 2025-07-03T11:01:02Z

2025-07-03 Direct Reconstruction of Terahertz-driven Subcycle Electron Emission Dynamics doi:10.57760/sciencedb.27400 en While field-driven electron emission is theoretically understood down to the subcycle regime, its direct experimental temporal characterization using long-wavelength terahertz (THz) fields remains elusive. Here, by driving a graphite tip with phase-stable quasi-single-cycle THz pulses, we reveal distinct subcycle electron emission dynamics including: (1) At a carrier-envelope phase (CEP) near zero, spectral peaks scale linearly with THz field strength, characteristic of subcycle emission; (2) At the opposite CEP, dominant deceleration fields generate stationary low-energy peaks. Crucially, we develop a pump-probe-free, direct reconstruction method extracting electron pulse profiles solely from measured energy spectra, obtaining durations from 97.3 to 114.3 fs as the field increases (191–290 kV/cm). Phase-resolved simulations further reveal a 71.2% modulation in the cutoff energy and a near-total (99.7%) suppression of the emission current. This work not only validates the Fowler-Nordheim model under THz excitation but also establishes a general framework for the direct temporal characterization of subcycle electron emission, opening pathways for precise electron control in ultrafast electron sources and lightwave nanoelectronics. Field emission; Terahertz; Time-domain characterization; CEP modulation Jiakang Mao Yushan Zeng Hongyang Li Liwei Song Ye Tian Ruxin Li PUBLIC https://creativecommons.org/licenses/by-nc-nd/4.0/ dataset http://www.doi.org/10.1103/z8pk-y8h8 Science Data Bank