To address the memristor existence questions: if you define a memristor as a device which "remembers" its resistance via a pinched hysteresis I-V curve, then we have had ReRAM/ memristor devices for some time now. On the other hand, if you define memristor as a device with coupling between charge and flux, then no.
Practically speaking, it's unlikely that memristors will replace transistors because they're about 500X too slow and have about a billion times less endurance. Same issue with memory replacement. They could in theory make excellent flash memory replacement, but currently sneak paths, thermal crosstalk and ion crosstalk remain challenges
Are memristors real? This paper[0] in addition to a handful that have appeared on HN in the last few months asserts that "the 2008 memristor is not the 1971 postulate and neither of them is fundamental" and moreover that "[t]he ideal memristor is an unphysical active device and any physically realizable memristor is a nonlinear composition of resistors with active hysteresis."
I'm confused by something like this being an open question, and even more confused about why this debate isn't lighting up the electrical/computer engineering community as far as I can tell.
I asked this question several years ago[0], and had some very interesting responses. The long and short of it was that yes, they are real, and you can make them yourself. The basic concept being that different metal oxides have different resistances; so if you make a "sandwich" like metal_1-oxide-metal_2 you can use current to move the oxygen ions from one metal to the other. The resistance of the sandwich changes as you do so, and stays set in between applications of charge, as well as staying set if the probing current is not too high. I recall making one was a fun afternoon project.
If you don't like the PR, just call it ReRAM. Few people actually care about HP's grandiose claims, a lot of people care about the actual performance of the devices.
> It’s also worth pointing out that all ideal circuit devices are non physical
This is not a useful statement - in this framing, all of circuit theory is unphysical.
Other ideal circuit elements could exist in the sense that their existence would not violate known physical laws. The criticisms of the memristor is that its existence would violate fundamental thermodynamic principles (esp. Landauer's principle).
I mean, an ideal voltage source also cannot exist, and I'm sure their existence would violate several laws of physics. For example what happens when you put two ideal voltage sources in parallel? or when you connect one to a short circuit?
Despite that though we can use a combination of ideal elements to represent real, non ideal, physical devices. So in that sense I disagree with your statement that "in this framing, all of circuit theory is unphysical."
To be faire, fusion plants lag on because either they are designed by people without enough resources, or by complex red-tape inducing collaboration.
ITER hoped to be done in 10 years starting in 2006, but they could only start in 2010 because every country wanted it to be built somewhere different.
Then, poor cooperation from Domestic Agencies caused frequent changes that were merged without hierarchical validation, causing the need for a full-time team whose only job was to detect inconsistencies post-hoc. Therefore, the planned completion in 2020 was pushed to 2025.
As a result, certain countries like the US made themselves begged to keep their promised investment.
... yes because that will be after the apocalypse and what remained of working pre-war technology were ancient "desktop computers". Big hulking things you couldn't put in your pocket, much less implant and connect to your brain. But they worked, and some source code was available. It was called "Linux".
Practically speaking, it's unlikely that memristors will replace transistors because they're about 500X too slow and have about a billion times less endurance. Same issue with memory replacement. They could in theory make excellent flash memory replacement, but currently sneak paths, thermal crosstalk and ion crosstalk remain challenges