Tag Archives: The Wire

Interactions, Collective Excitations and a Few Examples

Most researchers in our field (and many outside our field that study, e.g. ant colonies, traffic, fish schools, etc.) are acutely aware of the relationship between the microscopic interactions between constituent particles and the incipient collective modes. These can be as mundane as phonons in a solid that arise because of interactions between atoms in the lattice or magnons in an anti-ferromagnet that arise due to spin-spin interactions.

From a theoretical point of view, collective modes can be derived by examining the interparticle interactions. An example is the random phase approximation for an electron gas, which yields the plasmon dispersion (here are some of my own notes on this for those who are interested). In experiment, one usually takes the opposite view where inter-particle interations can be inferred from the collective modes. For instance, the force constants in a solid can often be deduced by studying the phonon spectrum, and the exchange interaction can be backed out by examining the magnon dispersions.

In more exotic states of matter, these collective excitations can get a little bizarre. In a two-band superconductor, for instance, it was shown by Leggett that the two superfluids can oscillate out-of-phase resulting in a novel collective mode, first observed in MgB2 (pdf!) by Blumberg and co-workers. Furthermore, in 2H-NbSe2, there have been claims of an observed Higgs-like excitation which is made visible to Raman spectroscopy through its interaction with the charge density wave amplitude mode (see here and here for instance).

As I mentioned in the post about neutron scattering in the cuprates, a spin resonance mode is often observed below the superconducting transition temperature in unconventional superconductors. This mode has been observed in the cuprate, iron-based and heavy fermion superconducting families (see e.g. here for CeCoIn5), and is not (at least to me!) well-understood. In another rather stunning example, no less than four sub-gap collective modes, which are likely of electronic origin, show up below ~40K in SmB6 (see image below), which is in a class of materials known as Kondo insulators.

smb6

Lastly, in a material class that we are actually thought to understand quite well, Peierls-type quasi-1D charge density wave materials, there is a collective mode that shows up in the far-infrared region that (to my knowledge) has so far eluded theoretical understanding. In this paper on blue bronze, they assume that the mode, which shows up at ~8 cm^{-1} in the energy loss function, is a pinned phase mode, but this assignment is likely incorrect in light of the fact that later microwave measurements demonstrated that the phase mode actually exists at a much lower energy scale (see Fig. 9). This example serves to show that even in material classes we think we understand quite well, there are often lurking unanswered questions.

In materials that we don’t understand very well such as the Kondo insulators and the unconventional superconductors mentioned above, it is therefore imperative to map out the collective modes, as they can yield critical insights into the interactions between constituent particles or couplings between different order parameters. To truly understand what is going on these materials, every peak needs to be identified (especially the ones that show up below Tc!), quantified and understood satisfactorily.

As Lestor Freamon says in The Wire:

All the pieces matter.

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Misconduct and The Wire

Season five of the critically acclaimed TV show The Wire tackles the issue of journalistic fraud and misconduct. In particular, Scott Templeton, a young ambitious journalist at the Baltimore Sun, writes a series of articles where he embellishes details, conjures up quotes out of thin air and ultimately fabricates events. His articles win him wide praise among those in the journalism community. He also garners the Pulitzer Prize, one of the highest accolades one can earn in the field. Even though flags are raised by some of his peers at the Baltimore Sun, at the upper management level, Scott Templeton’s stories are celebrated with enthusiasm.

Of course The Wire is fictional, but at the time The Wire was written, there was precedent for such journalistic falsification. Stephen Glass at the New Republic, Janet Cooke at the Washington Post and Jayson Blair at the New York Times had all been found guilty of journalistic misconduct associated with either plagiarism or fabrication in effort to advance their careers. Cooke was even awarded a Pulitzer Prize for her stories, which she eventually returned.

The reason I bring this all up is because I saw a very strong parallel between the fictional events that occurred in The Wire surrounding Scott Templeton and the actual events that occurred with respect to Jan-Hendrik Schon. In both cases, their notebooks were empty, there were claims by both that their information (e.g. data and notes) had somehow been corrupted and their sources were a closely guarded secret. While working at Bell Labs, Schon famously claimed to use the evaporator in Konstanz, Germany, so that he could “work” in isolation, making it more difficult to for others to reproduce his methods.

The question as to why this kind of misconduct takes place is an interesting one. In the case of Jayson Blair, Wikipedia says:

On the NPR radio show Talk of the Nation, Blair explained that his fabrications started with what he thought was a relatively innocent infraction: using a quote from a press conference which he had missed. He described a gradual process whereby his ethical violations became worse and contended that his main motivation was a fear of not living up to the expectations that he and others had for his career.

As can be gleaned from the quote above, there is little doubt that there is a certain amount of careerism and elevated expectation that is tied in with these instances of misconduct. That these and similar cases occur with relative frequency and happen in different fields suggests that the root cause is societal — an emphasis on perceived career success rather than valuing honesty and hard work. Because this is a sociological problem, all of us have a role to play in correcting it. The solution to the problem may require us to emphasize different values: integrity, meaningfulness of labor and honest motivations. Often these are not the qualities that advance one’s career, but this is because of a lack of emphasis on these values. Perhaps they should.

While the Wire is a fictional show and some readers are no doubt a little fed up with my frequent references to it, I do think that one can learn a lot from its main themes. As Tim O’Brien, author of The Things They Carried, said:

That’s what fiction is for. It’s for getting at the truth when the truth isn’t sufficient for the truth.

Metrics Subject to Manipulation

Previously, I have cited the famous HBO series The Wire focusing in particular on the careerism vs. good science dichotomy. A closely related element that I failed to mention last time was the use of a single number or metric to measure productivity or effectiveness of organizations or individuals. This problem is addressed in The Wire is many different contexts. In our field, the manifestation is in the form of the h-index, which is used for faculty hires, for department and university rankings and for assessing research grants. (A researcher has h-index h if he or she has published papers with at least h citations.)

It is well-known that measurements of this kind can lead to a corruption of sorts because people are susceptible to trying to maximize their indices. There are even ridiculous websites claiming they can help you increase your h-index. In The Wire, this is called “juking the stats”. Statistics can be “juked” is various ways. Researchers can request others to cite their work (and cite their own work heavily), undeserving co-authors may be included for minimal work, and pressure to publish can lead to sensationalized work that is “half-baked”, etc.

The detrimental side of these indices and metrics is captured well in a couple clips from The Wire linked below. The first is in the context of the police department in attempt to reduce crime rates and the second is in reference to test scores at the grade-school level.

https://www.youtube.com/watch?v=xH_6_8NOfwI

https://www.youtube.com/watch?v=_ogxZxu6cjM

It seems to me that there is some awareness and push-back in the physics community with respect to these metrics, which I find refreshing. I also think most of us recognize that blanket numbers like these cannot measure the subtleties associated with one’s true scientific output. Nonetheless, as long as the “higher-ups” continue to use them, the longer they will have a strong grappling-hook on some.

What THE WIRE Taught Me About Science

The famous HBO series, The Wire, which many have called the greatest television show of all time (e.g. here and here), has a lot to say about urban decay, race relations, and the structure of power and organizations . There is one theme that is particularly relevant to us in the sciences that The Wire profoundly addresses: the competition between careerism and good work.

In the series, many that get promoted in the hierarchical structure of the police department are not the best policemen, but the ones that are the most career-oriented. In one of the more memorable quotes on the show (even though there are so many!), Lt. Daniels says to Detective Carver, who is about to be promoted:

Couple weeks from now, you’re gonna be in some district somewhere with 11 or 12 uniforms looking to you for everything. And some of them are gonna be good police. Some of them are gonna be young and stupid. A few are gonna be pieces of shit. But all of them will take their cue from you. You show loyalty, they learn loyalty. You show them it’s about the work, it’ll be about the work. You show them some other kinda game, then that’s the game they’ll play. I came on in the Eastern, and there was a piece-of-shit lieutenant hoping to be a captain, piece-of-shit sergeants hoping to be lieutenants. Pretty soon we had piece-of-shit patrolmen trying to figure the job for themselves. And some of what happens then is hard as hell to live down. Comes a day you’re gonna have to decide whether it’s about you or about the work.

There is advice there for both advisers and students alike.

Advisers: (1) Pick students whose motivations lie in doing good work. (2) Show your students that what you do is about the work, about producing good science and not about publishing x hurried papers. (3) Help your students careers (honestly and without too much hype) when they aren’t looking (e.g. nominate them for awards, talk them up when you get the chance, etc.).

Students: (1) The adviser you pick will ultimately have a strong influence on where you end up and how you think about science in general; choose wisely. (2) Ask older graduate students, postdocs and professors questions; a large part of scientific development is figuring how/where to find interesting problems. (3) Do good work: Do not cut corners, do not hurriedly publish, be thorough and do not be dishonest.

In The Wire, there is a constant battle between the higher-ranked officials in the police department (who want to bring in low-level drug dealers under pressure from even higher-ranked officials and politicians), and the lower-ranked officials (who want to work a case until the entire case is solved so that they can bring in the drug kingpin and not just low-level middlemen). Fight the pressure to publish (to the best of your ability), and publish well when you do (sorry if you can’t see the analogy here!)

Alright, I’ll get off the soapbox now and just make one last comment: I have tried my best to follow these principles in graduate school (and have not always succeeded), but I do still think The Wire outlines a simple code to follow.

In the end, even in a show as pessimistic as The Wire, often good police got promoted and did their jobs better than the career-oriented ones. It is possible to do good work and survive even in this academic climate.

Also, if you’re a fan of The Wire, I recommend reading this: http://aaronhuertas.com/2011/11/what-i-learned-from-watching-the-wire-three-times/