Terahertz magnetic field enhancement in an asymmetric spiral metamaterial

dc.contributor.authorPolley, Debanjan
dc.contributor.authorHagström, Nanna Zhou
dc.contributor.authorKorff Schmising, Clemens von
dc.contributor.authorEisebitt, Stefan
dc.contributor.authorBonetti, Stefano
dc.date.accessioned2020-05-20T16:08:00Z
dc.date.available2020-05-20T16:08:00Z
dc.date.issued2018
dc.description.abstractWe use finite element simulations in both the frequency and the time-domain to study the terahertz resonance characteristics of a metamaterial (MM) comprising a spiral connected to a straight arm. The MM acts as a RLC circuit whose resonance frequency can be precisely tuned by varying the characteristic geometrical parameters of the spiral: inner and outer radius, width and number of turns. We provide a simple analytical model that uses these geometrical parameters as input to give accurate estimates of the resonance frequency. Finite element simulations show that linearly polarized terahertz radiation efficiently couples to the MM thanks to the straight arm, inducing a current in the spiral, which in turn induces a resonant magnetic field enhancement at the center of the spiral. We observe a large (approximately 20 times) and uniform (over an area of $\sim 10~\mu m^{2}$) enhancement of the magnetic field for narrowband terahertz radiation with frequency matching the resonance frequency of the MM. When a broadband, single-cycle terahertz pulse propagates towards the metamaterial, the peak magnetic field of the resulting band-passed waveform still maintains a 6-fold enhancement compared to the peak impinging field. Using existing laser-based terahertz sources, our metamaterial design allows to generate magnetic fields of the order of 2 T over a time scale of several picoseconds, enabling the investigation of non-linear ultrafast spin dynamics in table-top experiments. Furthermore, our MM can be implemented to generate intense near-field narrowband, multi-cycle electromagnetic fields to study generic ultrafast resonant terahertz dynamics in condensed matter.en
dc.description.sponsorshipEC/H2020/715452/EU/Understanding the speed limits of magnetism/MAGNETIC-SPEED-LIMITen
dc.identifier.eissn1361-6455
dc.identifier.issn0953-4075
dc.identifier.urihttps://depositonce.tu-berlin.de/handle/11303/11185
dc.identifier.urihttp://dx.doi.org/10.14279/depositonce-10076
dc.language.isoen
dc.rights.urihttps://creativecommons.org/licenses/by/3.0/
dc.subject.ddc530 Physikde
dc.subject.otherterahertzen
dc.subject.othermagnetic fielden
dc.subject.othermetamaterialsen
dc.titleTerahertz magnetic field enhancement in an asymmetric spiral metamaterialen
dc.typeArticleen
dc.type.versionpublishedVersionen
dcterms.bibliographicCitation.articlenumber224001
dcterms.bibliographicCitation.doi10.1088/1361-6455/aae579
dcterms.bibliographicCitation.issue22
dcterms.bibliographicCitation.journaltitleJournal of Physics B: Atomic, Molecular and Optical Physicsen
dcterms.bibliographicCitation.originalpublishernameIOP Publishingen
dcterms.bibliographicCitation.originalpublisherplaceBristolen
dcterms.bibliographicCitation.volume51
tub.accessrights.dnbfree
tub.affiliationFak. 2 Mathematik und Naturwissenschaften::Inst. Optik und Atomare Physik::FG Röntgenoptik und Nanometer-Optikde
tub.affiliation.facultyFak. 2 Mathematik und Naturwissenschaftende
tub.affiliation.groupFG Röntgenoptik und Nanometer-Optikde
tub.affiliation.instituteInst. Optik und Atomare Physikde
tub.publisher.universityorinstitutionTechnische Universität Berlinde

Files

Original bundle
Now showing 1 - 1 of 1
Loading…
Thumbnail Image
Name:
Polley_etal_2018.pdf
Size:
1003.52 KB
Format:
Adobe Portable Document Format

Collections