Quantum particle passes over a potential drop

[Verne]

A friend and I recently read this article in Scientific American:

http://www.sciam.com/article.cfm?id=new-quantum-weirdness

Now, it seems that this allegedly "new" quantum weirdness/anti-tunneling is nothing more than what you learn in your first semester of undergraduate quantum, i.e. the fact that when a quantum particle passes over a potential drop (instead of running into a potential barrier and possibly tunneling), some of the particle's wave may be reflected and some of it transmitted.

Yet Frank Wilczek of MIT says in the article that this anti-tunneling is an interesting phenomena he had not been conscious of before, which makes me hesitant to think the article is discussing a basic concept. Is this phenomenon not simply a reflected wave, and if not, what is it?

 

[Manilzin]

I agree, this seems to be the effect we learn about in basic quantum mechanics. The comment by Griffiths, and the fact that this "antitunneling" was given as an exercise in his textbook, as stated in this text, indicates that this indeed is not a new effect. Perhaps the novelty of this is that that physicist finally has been consciously aware of the effect? :) Seriously, I don't know. It seems some numerical analysis has been done to validate the effect, maybe that's what it is.

 

[Naty1]

Interesting post...thanks.

For antitunneling, the analogy is that whenever any wave encounters any abrupt change of conditions—even ones more favorable to its propagation—some of it will reflect back. ... To be sufficiently abrupt, the distance over which conditions change must be shorter than the wavelength (which for a particle is related to momentum). If the change is too gradual, the wave will simply go along, and the particle will act like a soccer ball after all.

Another illustration of "quantum weirdness"..."anything that can happen, will happen"

Perhaps "boundary conditions" play a more complex and subtle role on sub atomic scales than we understand!