[Physics] Superluminal phenomena and evidence thereof

[Arend Lammertink]

This one is also interesting:

http://www.tuks.nl/pdf/Reference_Material/Fast_Light/Broadband%20Superluminal%20Transmission%20Line%20with%20Non-Foster%20Negative%20Capacitor.pdf

Broadband Superluminal Transmission Line with Non-Foster Negative Capacitor

"Abstract—We present a superluminal transmission line (STL) loaded
with non-Foster negative capacitors. The loaded negative capacitors
decrease the effective capacitance and the effective permittivity of
the dielectric substrate of the TL. Since wave propagation velocity
depends on effective capacitance of the line, it can be higher than
the light speed c0 in vacuum. The superluminal line is simulated and
the results are compared to an experimental investigation of the
superluminal phase and group velocities that are extracted from
measured S- parameters.

[...]

CONCLUSION

In summary, this work reports a 3-unit-cell negative capacitor-loaded
superluminal transmission line. Measurements performed on the TL
present a superluminal propagation medium with a maximum of 1.2c0
phase velocity and 2.6c0 group velocity simultaneously over a
frequency bandwidth of 70 MHz with a maximum around 95 MHz,
corresponding to a bandwidth of 70%. This superluminal transmission
line demonstrates the efficiency of this approach and the possibility
to engineer broadband superluminal propagation using non-Foster
devices."


Note that in order to accomplish this, so-called "negative capacitors"
are being deployed. These are active components (includes an
amplifier) to create a component that acts as a capacitor with a
negative value.