dc.contributor.author
Müller, Melanie
dc.contributor.author
Sabanés, Natalia Martín
dc.contributor.author
Kampfrath, Tobias
dc.contributor.author
Wolf, Martin
dc.date.accessioned
2020-10-28T07:58:08Z
dc.date.available
2020-10-28T07:58:08Z
dc.identifier.uri
https://refubium.fu-berlin.de/handle/fub188/28677
dc.identifier.uri
http://dx.doi.org/10.17169/refubium-28425
dc.description.abstract
Coupling phase-stable single-cycle terahertz (THz) pulses to scanning tunneling microscope (STM) junctions enables spatiotemporal imaging with femtosecond temporal and Angstrom spatial resolution. The time resolution achieved in such THz-gated STM is ultimately limited by the subcyde temporal variation of the tip-enhanced THz field acting as an ultrafast voltage pulse, and hence by the ability to feed high-frequency, broadband THz pulses into the junction. Here, we report on the coupling of ultra-broadband (1-30 THz) single-cycle THz pulses from a spintronic THz emitter (STE) into a metallic STM junction. We demonstrate broadband phase-resolved detection of the THz voltage transient directly in the STM junction via THz-field-induced modulation of ultrafast photocurrents. Comparison to the unperturbed far-field THz waveform reveals the antenna response of the STM tip. Despite tip-induced low-pass filtering, frequencies up to 15 THz can be detected in the tip-enhanced near-field, resulting in THz transients with a half-cycle period of 115 fs. We further demonstrate simple polarity control of the THz bias via the STE magnetization and show that up to 2 V THz bias at 1 MHz repetition rate can be achieved in the current setup. Finally, we find a nearly constant THz voltage and waveform over a wide range of tip-sample distances, which by comparison to numerical simulations confirms the quasi-static nature of the THz pulses. Our results demonstrate the suitability of spintronic THz emitters for ultrafast THz-STM with unprecedented bandwidth of the THz bias and provide insight into the femtosecond response of defined nanoscale junctions.
en
dc.format.extent
10 Seiten
dc.rights.uri
https://creativecommons.org/licenses/by/4.0/
dc.subject
scanning tunneling microscopy
en
dc.subject
THz voltage sampling
en
dc.subject
spintronic THz emitter
en
dc.subject
broadband THz pulses
en
dc.subject
tip antenna response
en
dc.subject
ultrafast photocurrents
en
dc.subject.ddc
500 Naturwissenschaften und Mathematik::530 Physik::530 Physik
dc.title
Phase-Resolved Detection of Ultrabroadband THz Pulses inside a Scanning Tunneling Microscope Junction
dc.type
Wissenschaftlicher Artikel
dcterms.bibliographicCitation.doi
10.1021/acsphotonics.0c00386
dcterms.bibliographicCitation.journaltitle
ACS Photonics
dcterms.bibliographicCitation.number
8
dcterms.bibliographicCitation.pagestart
2046
dcterms.bibliographicCitation.pageend
2055
dcterms.bibliographicCitation.volume
7
dcterms.bibliographicCitation.url
https://doi.org/10.1021/acsphotonics.0c00386
refubium.affiliation
Physik
refubium.resourceType.isindependentpub
no
dcterms.accessRights.openaire
open access
dcterms.isPartOf.eissn
2330-4022
refubium.resourceType.provider
WoS-Alert