Author
Sheldon Schultz
Other affiliations: University of California, École Polytechnique Fédérale de Lausanne
Bio: Sheldon Schultz is an academic researcher from University of California, San Diego. The author has contributed to research in topics: Magnetization & Plasmon. The author has an hindex of 43, co-authored 135 publications receiving 26175 citations. Previous affiliations of Sheldon Schultz include University of California & École Polytechnique Fédérale de Lausanne.
Papers published on a yearly basis
Papers
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17 Jun 1996
TL;DR: In this paper, two-dimensional photonic crystals sandwiched between two metal conductors are used to control both the electromagnetic propagation and the radiation spectra in a waveguide, which can be completely suppressed in band gaps and enormously enhanced at specific pass bands frequencies.
Abstract: We study a new type of waveguide structures-two-dimensional photonic crystals sandwiched between two metal conductors. In the structures, not only the electromagnetic propagation, but also the radiation spectra can be controlled. Radiation from microwave dipole antennas can be completely suppressed in band gaps and enormously enhanced at specific pass bands frequencies.
3 citations
TL;DR: A modified mean-field theory incorporating spin clusters whose parameters are deduced from a fit to the data are formulated and a new cusp transition is identified whose locus is a line in the \ensuremath{\chi}-T plane, independent of x.
Abstract: Detailed measurements of the temperature and field dependence of the ac susceptibility \ensuremath{\chi} for the spin glass Cu-${\mathrm{Mn}}_{\mathrm{x}}$ reveal a new cusp transition whose locus is a line in the \ensuremath{\chi}-T plane, independent of x. We have formulated a modified mean-field theory incorporating spin clusters whose parameters are deduced from a fit to the data. We find a correlation length associated with the rotational coherence of the local field and identify the cusp line as a physical feature corresponding to the divergence of the correlation length at the transition temperature ${T}_{g}$. We find that our data are well represented by scaling relations both above and below ${T}_{g}$, and from these relations we evaluate the critical exponents \ensuremath{\delta}, \ensuremath{\gamma}, \ensuremath{\delta}', and \ensuremath{\gamma}'.
2 citations
TL;DR: In this article, the authors measured electron paramagnetic resonance (EPR), resistivity, and dc susceptibility from 2 to 300 K for the oxide high Tc superconductors (R)Ba2Cu3Oy (R=Y,Pr,Nd,Eu,Gd,Ho,Er,Tm, or Yb).
Abstract: We have measured electron paramagnetic resonance (EPR), resistivity, and dc susceptibility from 2 to 300 K for the oxide high Tc superconductors (R)Ba2Cu3Oy (R=Y,Pr,Nd,Eu,Gd,Ho,Er,Tm, or Yb). Selected systems were doped with 3‐d ions (Cr,Mn,Fe,Ni,Co, or Zn) or 4‐f ions (Gd or Er) which presumably substitute for the Cu or R site, respectively. In the systems studied we have observed an EPR line at low temperatures (T<40 K), which exhibits an increase in intensity and decrease in field for resonance as the temperature is lowered. The ESR linewidth is also temperature dependent and exhibits a minimum at about 15 K. An additional EPR line that can be associated with a Gd3+, Mn2+ or Er3+ ion was observed for those samples where these ions were present as dilute impurities. In some of the samples another EPR signal is observed with properties that depend on sample preparation conditions. The behavior and origin of all lines will be discussed. The variation of Tc with concentration of the added impurities over t...
2 citations
28 Oct 2003
TL;DR: In this paper, the effect of particle sizes with particle plasmon resonant wavelength and the coupling between pair of elliptical metallic disks and ellipsoid particles by simulations and experiments was studied.
Abstract: Nano gold particles interact strongly with visible light to excite the collaborative oscillation of conductive electrons within nano particles resulting in a surface plasmon resonance which makes them useful for various applications including bio-labeling. In this paper, we study the effect of particle sizes with particle plasmon resonant wavelength and the coupling between pair of elliptical metallic disks and ellipsoid particles by simulations and experiments. The red-shift resonant peak wavelength of coupled particles to that of single particle is due to particle plasmons near-field coupling. The shift decays is approximately exponentially with increasing particle spacing, and reaches zero when the gap between the two particles exceeds about 2.5 times the particle short axis length. It is also found that the exponential decay of peak shift with particle gap is size independent but shape dependent.
2 citations
TL;DR: In this article, a preparation procedure for Tl-Ba-Ca-Cu-O superconducting samples which can be levitated above or beneath a magnet is described and X-ray powder diffraction data for these samples are presented and discussed.
Abstract: A preparation procedure for the Tl-Ba-Ca-Cu-O superconducting samples which can be levitated above or beneath a magnet is described. X-ray powder diffraction data for these samples are presented and discussed. Their electronic and magnetic properties are presented. The explanation for the unusual levitation is briefly discussed.
2 citations
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TL;DR: By altering the structure of a metal's surface, the properties of surface plasmons—in particular their interaction with light—can be tailored, which could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved.
Abstract: Surface plasmons are waves that propagate along the surface of a conductor. By altering the structure of a metal's surface, the properties of surface plasmons--in particular their interaction with light--can be tailored, which offers the potential for developing new types of photonic device. This could lead to miniaturized photonic circuits with length scales that are much smaller than those currently achieved. Surface plasmons are being explored for their potential in subwavelength optics, data storage, light generation, microscopy and bio-photonics.
10,689 citations
TL;DR: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems as discussed by the authors, where the primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport.
Abstract: Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.
9,158 citations
TL;DR: These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root ofɛ·μ for the frequencies where both the permittivity and the permeability are negative.
Abstract: We present experimental scattering data at microwave frequencies on a structured metamaterial that exhibits a frequency band where the effective index of refraction (n) is negative. The material consists of a two-dimensional array of repeated unit cells of copper strips and split ring resonators on interlocking strips of standard circuit board material. By measuring the scattering angle of the transmitted beam through a prism fabricated from this material, we determine the effective n, appropriate to Snell's law. These experiments directly confirm the predictions of Maxwell's equations that n is given by the negative square root of epsilon.mu for the frequencies where both the permittivity (epsilon) and the permeability (mu) are negative. Configurations of geometrical optical designs are now possible that could not be realized by positive index materials.
8,477 citations
TL;DR: Recent advances at the intersection of plasmonics and photovoltaics are surveyed and an outlook on the future of solar cells based on these principles is offered.
Abstract: The emerging field of plasmonics has yielded methods for guiding and localizing light at the nanoscale, well below the scale of the wavelength of light in free space. Now plasmonics researchers are turning their attention to photovoltaics, where design approaches based on plasmonics can be used to improve absorption in photovoltaic devices, permitting a considerable reduction in the physical thickness of solar photovoltaic absorber layers, and yielding new options for solar-cell design. In this review, we survey recent advances at the intersection of plasmonics and photovoltaics and offer an outlook on the future of solar cells based on these principles.
8,028 citations
TL;DR: This work shows how electromagnetic fields can be redirected at will and proposes a design strategy that has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
Abstract: Using the freedom of design that metamaterials provide, we show how electromagnetic fields can be redirected at will and propose a design strategy. The conserved fields-electric displacement field D, magnetic induction field B, and Poynting vector B-are all displaced in a consistent manner. A simple illustration is given of the cloaking of a proscribed volume of space to exclude completely all electromagnetic fields. Our work has relevance to exotic lens design and to the cloaking of objects from electromagnetic fields.
7,811 citations