5614 Posted May 11, 2005 Posted May 11, 2005 Right... I understand quantum tunneling, I understand how it is used in quantum tunneling transistors, but I do not get how quantum tunneling is related to these pressure cables or buttons as seen here: Cable: http://www.maplin.co.uk/Module.aspx?ModuleNo=44296&doy=11m5 Pressure button: http://www.maplin.co.uk/Module.aspx?ModuleNo=44202&doy=11m5 How is tunneling, which is to do with particles crossing potential barriers or wells which they don't classically speaking have the energy to do, related to wires which: "When pressure is applied to the outside of the QTC cable the resistance of the QTC core changes from greater than 10M‡;, to less than 10‡; thus allowing current to flow from the outer braid to the inner central wire" Can anyone help?
Tom Mattson Posted May 11, 2005 Posted May 11, 2005 It appears that when the QTC core is unloaded the potential barrier to the electrons is (nearly) insurmountable. But when pressure is put on it, the "walls" of the barrier are moved closer together (thus decreasing the barrier width). When that happens, the barrier is much more easily crossed, and a non-negligible current starts flowing.
5614 Posted May 12, 2005 Author Posted May 12, 2005 Ohhh, and because we're talking an atomic scale [for the electrons jumping] they're super sensitive. So it's not really the resistance changing, more the reduction of the potential barrier, electronic retailers, what do they know about QM! Thanks though.
reverse Posted May 21, 2005 Posted May 21, 2005 Ok I admit, I was sleeping during most of my lectures...but I'm sure I was awake to hear the professor say that the electron ( or hole) never actually went anywhere...rather , another electron entirely appeared. or has that idea been upgraded since I last paid attention?
5614 Posted May 21, 2005 Author Posted May 21, 2005 But that'd disagree with the conservation of energy (and mass). It also goes against what I've read/learnt regarding quantum tunneling, so I don't think you are correct.
reverse Posted May 21, 2005 Posted May 21, 2005 Ah, who knows! he was a bit eccentric. wouldn’t have a bar of my "ether: in space theory.
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now