High visibility in two-color above-threshold photoemission from tungsten nanotips in a coherent control scheme. Issue 10 (17th June 2017)

• Record Type: Journal Article
• Authors: Paschen, Timo; Förster, Michael; Krüger, Michael; Lemell, Christoph; Wachter, Georg; Libisch, Florian; Madlener, Thomas; Burgdörfer, Joachim; Hommelhoff, Peter
• Is Part Of: Journal of modern optics. Volume 64:Issue 10/11(2017)
• Page Start: 1054
• Page End: 1060
• Publication Date: 2017-06-17
• Subjects: Nanotip -- electron emitter -- two-color laser field -- density functional theory; Optics -- Periodicals; 535
• DOI: 10.1080/09500340.2017.1281453
• Languages: English
• ISSNs: 0950-0340

Abstract

Abstract : In this article, we present coherent control of above-threshold photoemission from a tungsten nanotip achieving nearly perfect modulation. Depending on the pulse delay between fundamental ( 1560 n m ) and second harmonic ( 780 n m ) pulses of a femtosecond fiber laser at the nanotip, electron emission is significantly enhanced or depressed during temporal overlap. Electron emission is studied as a function of pulse delay, optical near-field intensities, DC bias field and final photoelectron energy. Under optimized conditions modulation amplitudes of the electron emission of 97.5% are achieved. Experimental observations are discussed in the framework of quantum-pathway interference supported by local density of states simulations.