1,721,065 research outputs found
Optical generation of intense ultrashort magnetic pulses at the nanoscale
No full textGenerating, controlling and sensing strong magnetic fields at ever shorter time and length scales is important for both fundamental solid-state physics and technological applications such as magnetic data recording. Here, we propose a scheme for producing strong ultrashort magnetic pulses localized at the nanoscale. We show that a bimetallic nanoring illuminated by femtosecond laser pulses responds with transient thermoelectric currents of picosecond duration, which in turn induce Tesla-scale magnetic fields in the ring cavity. Our method provides a practical way of generating intense nanoscale magnetic fields with great potential for materials characterization, terahertz radiation generation and data storage applications
Element-Specific Probing of Ultrafast Magnetization Dynamics in the Visible Spectral Range
No full textFemtosecond laser excitation of thin magnetic films consisting of multiple magnetic sublattices triggers ultrafast spin dynamics and even magnetization reversal driven by the exchange interaction between the sublattices. To explore these intriguing phenomena requires element specific studies.We demonstrate that element specific probing of ultrafast spin dynamics can also be realized with visible light and does not require sophisticated X-ray facilities
Direct Observation of strain-induced second harmonic generation in Co0.25Pd0.75 thin film on Pb(ZrTi)O3 substrate
No full textUltrafast spectroscopy with spin polarization
No full textA project for the design and r.alization of an experimental station dedicated to ultrafast spin polarization dynamics allowing for spin polarization measurements of photoelectron yield as excited by free electron laser pulses is presented
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Second-harmonic generation from realistic film-substrate interfaces: The effects of strain
No full textThe optical second-harmonic generation from a thin crystalline film on a substrate is theoretically investigated for both s and p polarized incident light. The contributions of lattice misfit strain as well as of misfit dislocation strain to the second-order nonlinear optical susceptibility are described using a nonlinear photoelastic tensor and can be separated by a polarization analysis of the scattered light at the second harmonic frequency. For the s(omega)--> s(2 omega) and p(omega)--> s(2 omega) scattering geometries, the nonlinear optical signal will be determined by dislocation strain only, whereas for the s(omega)--> p(2 omega) and p(omega)--> p(2 omega) geometries both lattice misfit strain and misfit dislocation strain will contribute. (C) 2000 American Institute of Physics. [S0003-6951(00)01814-3].This work was supported in part by INTAS, Grant No.
97-0705. One of the authors ~I.L.L.! acknowledges KISTEP
for financial support for his visit to Korea and is also very
grateful to the CNSM and the Physics Department of KAIST
for the hospitality extended during his stay in Taejon
Alignment of nematic liquid crystals on an electrically poled photopolymer film
No full textWe have observed liquid crystal alignment on an electrically poled polyvinylcinnamate film in which a polar symmetry was introduced by an in-plane electric field and stabilized by unpolarized ultraviolet light. The azimuthal anchoring energy and pretilt angle was measured in a twisted nematic or planar cell and is explained via the molecular structure of the unreacted cinnamates and of the photoproducts beta -truxinates. Cinnamates mainly contribute via a strong flow alignment, while beta -truxinate produces the anisotropic properties of the film such as its polar anisotropy, azimuthal anchoring, and pretilt angle. (C) 2001 American Institute of Physics
Influence of lattice mismatch on magnetization-induced optical second harmonic generation from a magnetic film on a nonmagnetic substrate
No full textThe optical second harmonic generation from a thin magnetic film on a nonmagnetic substrate is theoretically investigated for both s- and p-polarized incident light. The contributions of lattice misfit strain as well as of misfit dislocation strain to the second-order nonlinear optical susceptibility are described using a nonlinear photoelastic tensor, together with the contribution of magnetization described by a nonlinear magneto-optical tensor. (C) 2000 American Institute of Physics. [S0021-8979(00)27308-8].This work was supported in part by INTAS, Grant No.
97-0705. The authors would like to thank J. Sherer for a
critical reading of this manuscript. One of the authors
~I.L.L.! acknowledges KISTEP for financial support for his
visit to Korea. He is also grateful to the Center for Nanospinics
of Spintronic Materials and the Physics Department
of KAIST for the hospitality extended during his stay in
Taejon
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