Just a few years ago, if you wanted to look for recent research articles about quantum entanglement, you would check out the quantum physics [quant-ph] archive at arXiv.org. Since 1994, quant-ph has been the central repository for papers about quantum computing and the broader field of quantum information science. But over the past few years there has been a notable change. Increasingly, exciting papers about quantum entanglement are found at the condensed matter [cond-mat] and high energy physics – theory [hep-th] archives.

I don’t know for sure, but that trend may have had something to do with an invitation I received a few months ago from David Gross, to organize the next Jerusalem Winter School in Theoretical Physics. David has been the General Director of the School for, well, I’m not sure how long, but it must be a long time. In the past, the topic of the school has rotated between particle physics, condensed matter physics, and astrophysics. Every year, a group of world-class scientists gives lectures on cutting-edge research for an enthusiastic audience of postdoctoral scholars and advanced graduate students.

David suggested that a good topic for the next school would be “quantum information, broadly envisaged — from quantum computing to strongly correlated electrons.” After some hesitation for family reasons, I embraced this opportunity to amplify David’s message: quantum information has arrived as a major subfield of physics, and its relevance to other areas of physics is becoming broadly appreciated.

I’m not good at organizing things myself, so I recruited two friends who are very good at it to help me: Michael Ben-Or and Patrick Hayden. As the local organizer at The Hebrew University, Michael has to do a lot of the hard work that I’m glad to avoid. We decided to call the school “Frontiers of Quantum Information Science,” and put together a slate of 10 lecturers, which I’m very excited about. The lectures will cover the core areas of quantum information, as well as some of the important ways in which quantum information relates to quantum matter, quantum field theory, and quantum gravity. Each lecturer will give three or four ninety-minute lectures, on these topics:

**Scott Aaronson** (MIT), Quantum complexity and quantum optics

**David DiVincenzo** (Aachen), Quantum computing with superconducting circuits

**Daniel Harlow** (Princeton), Black holes and quantum information

**Michal Horodecki** (Gdansk), Quantum information and thermodynamics

**Stephen Jordan** (NIST), Quantum algorithms

**Rob Myers** (Perimeter), Entanglement in quantum field theory

**Renato Renner** (ETH), Quantum foundations

**Ady Stern** (Weizmann), Topological quantum computing

**Barbara Terhal** (Aachen), Quantum error correction

**Frank Verstraete** (Vienna), Quantum information and quantum matter

The school will run from 30 December 2013 to 9 January 2014 at the Israel Institute for Advanced Studies at The Hebrew University in Jerusalem. If you are interested in attending, please visit the website for more information and fill out the registration form by November 1. I hope you can come — it’s going to be a lot of fun.

Rereading the first paragraph of this post, I got slightly nervous about whether the trend I described can be documented, so I have done a little bit of research. Going back to 2005, I plotted the number of papers with the word “entanglement” in the title on quant-ph, cond-mat, hep-th, and also the general relativity and quantum cosmology [gr-qc] archive. For 2013, I rescaled the data for the year up to now, taking into account that Sep. 22 is the 265th day of the year. I didn’t make any adjustment for papers being cross-listed on multiple archives.

Here is the data for quant-ph:It’s remarkably flat. Here is the aggregated data for the other three archives:It’s pretty clear that something started to happen around 2010. I realize one could do a much more serious study of this issue, but since I was only willing to spend an hour on it, I feel vindicated.

You should be controlling for the general increase in the number of papers as our communities grow in size. Here is a plot of the percentage of articles containing the word “entanglement” on each of the three non-quantum arxiv subject classes that you consider: http://cl.ly/1V3j402b2G0q . The trend is real, and extends back to somewhere between 2001–2003.

Indeed, if you plot the percentage of “entanglement” articles for quant-ph then it is flat since 2005, and possibly slightly decreasing since 2009.

Thanks, Steve. That bookworm arXiv is a cool site; I hadn’t seen it before.

A possible reason for this is that people from areas like HEP and condensed matter are changing to quantum information because it is a growing subject with healthy funding. They have submission rights for their old field on arXiv but not quant-ph. Rather than taking the trouble find an endorser for quant-ph where their new work belongs they just post where they can, ie. hep-th etc. The other possibility is that entanglement is relevant to research in these other fields, e.g. the firewall problem, so these are not really quantum information papers at all.

I think the relevance of entanglement to other fields is the dominant effect.

Some one contact me please

Many worlds theory WRONG

Replace different world with Time

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