poor mans superconductor wire

[Jamie M]

Hi,

I was thinking of an alternative to superconductors to transmit
electricity with low (or zero) resistance. If there is a wire used
which has a fixed resistance but is able to regenerate some of the lost
energy that is lost to resistance, then it would have an effective
resistance that is lower. I think they key is to structure the wire
so the losses happen in a way that they can be regenerated. I was
thinking maybe something like a diode could work. ie. The wire would
be a stretched diode turned sideways, so that the P and N of the
diode are at the start of the wire and also the same P and N sections
are at the end of the wire. Then if the current is sent down the
interface of the diode between the P and N on the anode side, then if
there is resistance in the "wire", it will create phonons at the diode
junction, and they can be pumped by the diode back into the wire if the
cathode of the diode is routed back to the anode at the area that the
electrical loss occurs. Would something like this work? It is similar
to a solar panel for collecting electricity, but instead of using
photons from the sun, it is using phonons from electrical resistance
losses.

cheers,
Jamie

 

[Tim Williams]

Electrons are too heavily scattered at room temperature, and aren't
scattered with enough energy to notice. Thermal velocity is around 50
km/s (26meV), while electron drift velocity is on the order of 0.01 m/s
(depends on doping, charge density and current density), 10^5 times less.

Perhaps an extremely low temperature (i.e., 10^5 times less than 300K
ambient) would make the scattering more significant (however, scattering
is also thermally driven, which is why silicon resistors and FET channels
have a positive tempco), but you still need a semiconductor junction with
microvolt bandgap. That probably doesn't exist, or is too small (or too
tricky to tune by composition) to matter.

You might have more luck with a really fancy approach (which is to say,
not much), like, suppose the scattering could be made coherent, to make
coherent phonons (a phonon laser -- such a thing has been demonstrated).
Then suppose an acoustic multiplier could be made, to generate harmonics.
A few orders of magnitude later and the phonons will be on the order of
100s meV, potentially enough to play with at room temperature, or capture
with the help of a low bandgap semiconductor.

Tim

 

[Jamie M]

Electrons are too heavily scattered at room temperature, and aren't
scattered with enough energy to notice. Thermal velocity is around 50
km/s (26meV), while electron drift velocity is on the order of 0.01 m/s
(depends on doping, charge density and current density), 10^5 times less.

Perhaps an extremely low temperature (i.e., 10^5 times less than 300K
ambient) would make the scattering more significant (however, scattering
is also thermally driven, which is why silicon resistors and FET channels
have a positive tempco), but you still need a semiconductor junction with
microvolt bandgap. That probably doesn't exist, or is too small (or too
tricky to tune by composition) to matter.

You might have more luck with a really fancy approach (which is to say,
not much), like, suppose the scattering could be made coherent, to make
coherent phonons (a phonon laser -- such a thing has been demonstrated).
Then suppose an acoustic multiplier could be made, to generate harmonics.
A few orders of magnitude later and the phonons will be on the order of
100s meV, potentially enough to play with at room temperature, or capture
with the help of a low bandgap semiconductor.

Tim

Hi,

Thanks thats interesting, I think a "phonon standing wave" that keeps
the electrons lined up and travelling straight with no losses could work
maybe. Maybe a dual bandgap (cathode to cathode diode) with the
electrons confined to travel only in the cathode area to hold them
locked into that straight path down the wire.

cheers,
Jamie