Bob Cook wrote:
| I am about 2/3 through the paper you identified on the transmission
of a
| terahertz electric field wave form through Ni and Co particles in a
static
| magnetic field.
... Just to clarify, this is a reference that Jones cited and I just gave a
link to it that wasn't behind a pay wall. Perhaps Jones may comment also to
your questions...
| Does the oscillating terahertz electric field produce a perpendicular
| oscillating magnetic field? Or does that only happen with photon
| propagation?
Yes it does. The Terahertz Electromagnetic Field is a "photon field", and
it will induce a magnetization. This is a very weak H Field compared to the
applied static magnetic field, but the localized magnetic field strength
would depend on any amplification produced by the generation of the Surface
Plasmon-Polariton (SPP) or whatever quasi-particle coupling might occur...
| Would a terahertz laser have a different effect? And would you see
| a phase change in the transmission of the beam through the Ni and Co
| particles?
My guess is that a Terahertz (THz) Laser (being more intense) would increase
the effect. The technique used in the paper is indeed sensitive to phase
changes. The THz pulse-induced phase change of the probe beam is converted
into an intensity modulation. They are using a Ti:sapphire Mode-Locked
Laser to initially generate the pulse beam fed into the THz Emitter and the
probe beam. I'm not sure I'm addressing your question, here. Perhaps you
can elaborate...
| If the changing electric field does in fact cause a changing magnetic
field,
| it would seem that it may introduce some impedence in the transfer of
| the electric field and account for the slight unexplained phase
change
| reported with respect to the electric field wave form after passing
through
| the film of the particle assemblege.
... I'm not sure it's possible to disagree with your statements above. Can
you possibly point to the unexplained phase shift that you are referring to,
so that I may comment? I believe they see a phase shift for both uncoated
and coated microparticles. Are you referring to all of the results, given?
The THz Probe Pulse is 800 nm Wavelength and could be exciting SPPs,
optically (vs. Terahertz) if I understand the setup correctly. Here is a
link to Ref. 19 which describes the experimental setup (hopefully you can
get to the paper):
http://www.opticsinfobase.org/oe/abstract.cfm?uri=oe-17-8-6600
| Do you know what the "N metal film" is that the authors stated was
applied
| to the Ni and Co particles in discussing the experimental set-up?
Should
| that be "no metal film"?
N-Metal Film in this case, refers to Nonmagnet Film (or Non-Ferromagnetic or
Normal vs. Ferromagnetic, "F"). This can be very confusing because
hard-core "Plasmonic" people sometimes refer to N-Metal Films as Noble Metal
Films (which are extensively used in the paper), but if they were to mention
it this way they would be very clear about it, unlike Spin Freaks (just
kidding!).
- Mark Jurich
