David Friedberg

But can you tell us what quantum tunneling is?

So this is another one of these sort of features of quantum mechanics that arises from the fact that these things are kind of waves and probability functions.

So this is what's so interesting.

You can actually predict the number of electrons that might tunnel through

one of these barriers, one of these insulating barriers, as they're called, over to the other side, which really is crazy to think about.

It's just like walking through walls, right?

Yeah.

So going back to the story you were sharing, you're in grad school.

And then Leggett proposes this idea.

Maybe you can share a little bit more now that we've got, I think, a bit of the basics on what was discussed, which was zooming out a bit, like, rather than just think about all of this happening at a microscopic scale, is it possible for it to happen at a bigger scale?

Let me just kind of describe another way.

The macroscopic system could be my entire body.

Could I walk through a wall?

And then the probability of all of my atoms being in the perfect moment, perfect position, you know, to be able to kind of cross through the wall is so low, it would never happen in this or many other universes.

So there's a small probability one electron can cross over a barrier.

But the probability that many cross over at once is lower and lower and lower, and that makes it very difficult to see at scale.

So one of the parts of your experiment, you created what's called a Josephson junction.

Is that correct?

That's correct.

So this is two superconductors with a barrier between them, right?