arXiv subjects

P. N. Bartlett

Publications and source records attributed to P. N. Bartlett.

4 recordsLinked to original sources

arXiv2005

Plasmonic bandgaps and Trapped Plasmons on Nanostructured Metal Surfaces

Nanostructured metal surfaces comprised of periodically arranged spherical voids are grown by electrochemical deposition through a self-assembled template. Detailed measurements of the angle- and orientation-dependent reflectivity reveal the spectral dispersion, from which we identify the presence of both delocalized Bragg- and localized Mie-plasmons. These couple strongly producing bonding and anti-bonding mixed plasmons with anomalous dispersion properties. Appropriate plasmon engineering of the void morphology selects the plasmon spatial and spectral positions, allowing these plasmonic crystal films to be optimised for a wide range of sensing applications.

physics.optics↗

arXiv2004

Oscillatory Thickness Dependence of the Coercive Field in Magnetic 3D Anti-Dot Arrays

We present studies on magnetic nano-structures with 3D architectures, fabricated using electrodeposition in the pores of well-ordered templates prepared by self-assembly of polystyrene latex spheres. The coercive field is found to demonstrate an oscillatory dependence on film thickness reflecting the patterning transverse to the film plane. Our results demonstrate that 3D patterned magnetic materials are prototypes of a new class of geometrical multilayer structures in which the layering is due to local shape effects rather then compositional differences.

cond-mat.mes-hall↗

arXiv2004

Tunable Resonant Optical MicroCavities by Self-Assembled Templating

Micron-scale optical cavities are produced using a combination of template sphere self-assembly and electrochemical growth. Transmission measurements of the tunable microcavities show sharp resonant modes with a Q-factor>300, and 25-fold local enhancement of light intensity. The presence of transverse optical modes confirms the lateral confinement of photons. Calculations show sub-micron mode volumes are feasible. The small mode volume of these microcavities promises to lead to a wide range of applications in microlasers, atom optics, quantum information, biophotonics and single molecule detection.

physics.optics↗

arXiv2003

Superconducting anti-dot arrays from self-assembly template methods

We present results of electrochemical deposition of superconducting Pb in the pores of templates prepared by self-assembly from colloidal suspensions of polystyrene latex spheres. This technique enables us to create highly ordered superconducting nano-structures with 3D architectures on length scales ranging from 50 - 1000 nm. The prepared samples show pronounced Little-Parks oscillations in Tc and matching effects in magnetization and magnetic susceptibility. Real and imaginary parts of susceptibility follow a universal Cole-Cole curve. Self-field effects play an important role in commensurability behaviour of magnetic moment at low temperatures.

cond-mat.supr-con↗