Zero Point Laser
Posted: Wed Mar 20, 2013 5:17 am
Ex nihilo: Dynamical Casimir effect in metamaterial converts vacuum fluctuations into real photons
March 8, 2013
by Stuart Mason Dambrot
Image
(a) Equivalent electrical and mechanical circuits: the modulation of the Josephson inductance in the metamaterial by a magnetic φext varies the wave length λ with respect to the cavity length, which is analogous to modulating the effective length d of the cavity by mechanical means. The coupling capacitor is equivalent to a semitransparent mirror. (b) Schematics of the measurement setup. The metamaterial sample is a 4-mm-long coplanar waveguide with 250 embedded SQUIDs, each junction having a critical current of ~ 10 μA. The modulation of the flux through the SQUIDs is realized through a lithographically fabricated spiral coil underneath the metamaterial. (c) Resonant frequency ωres/2π vs. reduced magnetic flux φext/φ0 without the pump signal; the DC operating point for DCE experiments is denoted by a green circle. The inset displays the measured phase of the scattering parameter S11 while sweeping frequency, which yields d arg(S11)/dφext = d arg(S11)/dfÍdf/dφext . The steepness of the variation in the phase arg(S11) governs the effective "movement of the mirrors". Copyright © PNAS, doi:10.1073/pnas.1212705110
(Phys.org) —In the strange world of quantum mechanics, the vacuum state (sometimes referred to as the quantum vacuum, simply as the vacuum) is a quantum system's lowest possible energy state. While not containing physical particles, neither is it an empty void: Rather, the quantum vacuum contains fluctuating electromagnetic waves and so-called virtual particles, the latter being known to transition into and out of existence. In addition, the vacuum state has zero-point energy – the lowest quantized energy level of a quantum mechanical system – that manifests itself as the static Casimir effect, an attractive interaction between the opposite walls of an electromagnetic cavity. Recently, scientists at Aalto University in Finland and VTT Technical Research Centre of Finland demonstrated the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity. They showed that under certain conditions, real photons are generated in pairs, and concluded that their creation was consistent with quantum field theory predictions.
March 8, 2013
by Stuart Mason Dambrot
Image
(a) Equivalent electrical and mechanical circuits: the modulation of the Josephson inductance in the metamaterial by a magnetic φext varies the wave length λ with respect to the cavity length, which is analogous to modulating the effective length d of the cavity by mechanical means. The coupling capacitor is equivalent to a semitransparent mirror. (b) Schematics of the measurement setup. The metamaterial sample is a 4-mm-long coplanar waveguide with 250 embedded SQUIDs, each junction having a critical current of ~ 10 μA. The modulation of the flux through the SQUIDs is realized through a lithographically fabricated spiral coil underneath the metamaterial. (c) Resonant frequency ωres/2π vs. reduced magnetic flux φext/φ0 without the pump signal; the DC operating point for DCE experiments is denoted by a green circle. The inset displays the measured phase of the scattering parameter S11 while sweeping frequency, which yields d arg(S11)/dφext = d arg(S11)/dfÍdf/dφext . The steepness of the variation in the phase arg(S11) governs the effective "movement of the mirrors". Copyright © PNAS, doi:10.1073/pnas.1212705110
(Phys.org) —In the strange world of quantum mechanics, the vacuum state (sometimes referred to as the quantum vacuum, simply as the vacuum) is a quantum system's lowest possible energy state. While not containing physical particles, neither is it an empty void: Rather, the quantum vacuum contains fluctuating electromagnetic waves and so-called virtual particles, the latter being known to transition into and out of existence. In addition, the vacuum state has zero-point energy – the lowest quantized energy level of a quantum mechanical system – that manifests itself as the static Casimir effect, an attractive interaction between the opposite walls of an electromagnetic cavity. Recently, scientists at Aalto University in Finland and VTT Technical Research Centre of Finland demonstrated the dynamical Casimir effect using a Josephson metamaterial embedded in a microwave cavity. They showed that under certain conditions, real photons are generated in pairs, and concluded that their creation was consistent with quantum field theory predictions.
