Tag Archives: fourth circuit element

To be or not to be the memristor?

The memristor (aka, memresistor), for anyone not familiar with it, is a contested ‘new’ circuit element. In my April 5, 2010 posting I gave a brief overview of the history as I understood it (the memristor was a new addition to the traditional circuit elements [the capacitor, the resistor, and the inductor]) and in my April 7, 2010 posting I conducted an interview with Forrest H Bennett III who presented an alternative view to the memristor as ‘new’ circuit element discussion.

Discussion has continued on and off since then but in the last few weeks it has become more topical with the publication of a paper (Memresistors and non-memristive zero-crossing hysteresis curves) by Blaise Mouttet at arXiv.org on Jan. 12, 2012.

I don’t feel competent to summarize the gist of Blaise’s paper so I’m excerpting a passage *from* Peter Clarke’s Jan. 18, 2012 article for EE (Electronic Engineering) Times,

Blaise Mouttet argues that the interpretation of the memristor as a fourth fundamental circuit element – after the resistor, capacitor and inductor – was incorrect and that the memory device under development at HP Labs is not actually a memristor but part of a broader class of variable resistance systems.

Since publishing his arXiv paper Mouttet has also been in discussion with an e-mailing list of researchers into non-volatile memory device physics.

Some e-mail correspondents have come out in favor of Mouttet’s position stating that trying to define any two-terminal device in which the resistance can be altered by the current passed through the device as a memristor, adds nothing to the understanding of a complex field in which there are many types of device.

The article and the comments that follow (quite interesting and technical) are worth reviewing if this area of nanoelectronics interests you.

HP Labs has responded to Blaise’s paper and subsequent debate, and before included an excerpt from the response, I want to include a few passages from Blaise’s paper,

The “memristor” was originally proposed in 1971by Leon Chua as a missing fourth fundamental circuit element linking magnetic flux and electric charge. In 2008 a group of scientists from HP led by Stan Williams claimed to have discovered this missing memristor . It is my position that HP’s “memristor” claim lacks any scientific merit. My position is not that the HP researchers have presented an incorrect model of a memristor or even an incorrect model of resistance memory. If this were the case it would not be so bad because an incorrect model could at least be proven incorrect and possibly corrected to produce a better model. My position is that the HP researchers have avoided presenting any scientifically testable model at all by hiding behind the reputation of Leon Chua and the mythology of the memristor. They have thus attempted to bypass the principle of the scientific method.

If the HP researchers had developed a realistic model for resistive memory (whether it is called “memristor” or by some other name) it could be vetted by other researchers, compared to experimental data, and determined to be true or false. If necessary the model could be modified or corrected and an improved version of the model could be produced.

This is not what has happened. (p. 1 PDF)

Here’s my excerpt of HP’s response (from Peter Clarke’s Jan. 20, 2012 article for EE Times),

The spokesperson said in email: “HP is proud of the research it has undertaken into memristor technology and the recognition this has received in the scientific community. In a little over three years, our papers, which were subject to rigorous peer review before being published in leading scientific journals, have been cited more than 1,000 times by other researchers in the field. We continue this research and collaboration with the electronics industry to bring this important technology to market.”

Deciding what something is and how fits into our understanding of how the world operates, in this case, a new circuit element, or not, has consequences beyond the actual discussion. If science is the process of posing questions, we need to test the assumptions we make (in this case, whether or not the memristor is a fourth circuit element or part of a larger system of variable resistance systems) as they can define the questions we’ll ask in the future.

As I noted earlier, I’m not competent to draw any conclusions as to which party may have the right approach but I am glad to see the discussion taking place.

*’from’ added on Sept. 27, 2016.