Repulsion III: Out of Equilibrium

  Radiation Pressure counteracting Casimir attraction

 Transparent electrodes, e.g. Indium Tin Oxide (ITO)

 32 mW of laser power can neutralize the Casimir attraction from ITO at 100 nm.

 Thermal radition from plates at different temperatures can lead to repulsion

 Around room temperature, this is for distances exceeding 7 microns; too large for practical applications.

 At short separations contributions from evanescent waves are important.

 "Casimir-Lifshitz force out of thermal equilibrium,"

M. Antezza, L.P. Pitaevskii, S. Stringari, V.B. Svetovoy, Phys. Rev. A 77, 022901 (2008)

Generalizing Lifshitz, computes the Casimir force between plates at different temperatures.

 Resonance phenomena can be utilized to generate repulsion between atoms at different temperatures

 "Resonant Enhancement and Dissipation in Nonequilibrium van der Waals Forces,"

A.E. Cohen and S. Mukamel, Phys. Rev. Lett. 91, 233202 (2003)

 Can such a mechanism be used to generate repulsion between plates (made of materials with approiate resonances, and held at different temperatures)?

G. Bimonte, T. Emig, and M. Kardar (2010): Repulsion appears impossible at small separations.

  Plank's law can be modified for small objects, and short separations.

 "Probing Planck’s Law with Incandescent Light Emission from a Single Carbon Nanotube,"

Y. Fan, S.B. Singer, R. Bergstrom, & B.C. Regan, Phys. Rev. Lett.102, 187402 (2009)

 "Surface Phonon Polaritons Mediated Energy Transfer between Nanoscale Gaps,"

S. Shen, A. Narayanaswamy, & G. Chen, Nano Lett. 9, 2909 (2009)

  Need a generalizing of scattering approach to arbitrary shapes and materials to discuss Casimir forces, as well as radiation and heat transfer, for objects at micro and nano-scale.