# Negative resistance!

http://www.technologyreview.com/view/518426/how-to-save-the-troubled-graphene-transistor/

That's what they're trying... but is negative resistance? Even resistance eg 5v 200ohm resistor positive resistance?

I should google negative resistance lol

Yes. You should. Nothing magic here, just a property of certain materials under certain conditions.

A negative resistor is just an "amplifier".

cjdelphi:
but is negative resistance?
I should google negative resistance lol

Negative resistance is the counterintuitive phenomenon in which a current entering a material causes the voltage across it to drop

Their idea is to take a standard graphene field-effect transistor and find the circumstances in which it demonstrates negative resistance (or negative
differential resistance, as they call it). They then use the dip in voltage, like a kind of switch, to perform logic.

Tunnel diodes have been around since the '50s and they demonstrate negative resistance characteristics for at least part of their operating range. Nothing too new here.

I experienced negative resistance last night... was a bit baffled until I realize the peltier chip I was measuring the resistance on had a 'potential difference' (heat) and was giving off electricity :)

They are talking differential negative resistance, not absolute (which involves providing electrical power).

Differential negative resistance just means the V/I graph has negative slope at some points, not
that the value of V/I is negative.