The number one most irritating question I was asked during my faculty interviews was “what will you do if quantum computation doesn’t pan out?” At first glance this question seems perfectly valid: a department should concern itself with whether they are hiring someone whose work will quickly become irrelevant. But I’ve got news for you all, quantum computing’s not going away! Why? Well not for the reason the question askers are thinking: what happens if a quantum computer can’t be built? No, quantum information science will stick around because it has an intrinsic intellectual value. And this is what makes the question so irritating: it implies that quantum information science is a fad with no intrinsic intellectual value. Do you ask string theorists whether what they do will be experimentally testable and if not what will they do? Do you ask astrophysicists whether studying cosmology will have any significant impact on society? No. But because these are part of a long tradition of theoretical physics they are acceptable intellectual persuits, whereas quantum information science, being new and getting too much press is most definitely suspect.
There is, of course, great irony in this situation. Theoretical physics has always justified a large portion of it’s work as for the greater intellectual good (holier-than-thou-physics.) But mention the word “quantum” all of a sudden normally elitist physicists turn into engineers. The psychology behind this is pretty simple in my opinion (wait this whole thing is my opinion!): physicists have yet to actually accept quantum theory. They don’t want to think about it because it’s strange. The fact that it’s current position is basically to serve as the operating system of the universe doesn’t help at all. Because we can separate the axioms of quantum theory nicely from the physics of the fundamental forces most physicists can spend their entire life living, breathing, and calculating classically. Rather embarrasing for a group which seeks to understand the fundamentals of our universe.
O brave new quantum world!
I disagree that it’s got anything to do with things being quantum, but agree with your main point: qis is new, it gets a lot of press, parts of it look unfamiliar and maybe like maths or computer science, therefore it comes under a lot of suspicion.
I received a rather amusing assessment of a grant application once, in which the reviewer complained that I hadn’t demonstrated very much breadth compared with other young Australian theoretical physicists. Leaving aside whether that’s true or not, I strongly suspect that what they really meant was “all your papers are concerned with this weird quantum information stuff, ergo you must be narrow”.
I think the typical approach of a physicist in QC, is slightly different from that of a typical, say hep-th physicist, who works according to “divide et impera”, as you just wrote: “we can separate the axioms of quantum theory nicely from the physics of the fundamental forces”. In QC the main challenge is to bring back what we separated in the first place. Thus the approach is not purely that of a physicist, but that of maybe a mathematician, or even a chemist [What am I talking about?], but not of an engineering scientist.
I was asked a similar question, by a member of my PhD qual committee [a theorist, no less], on the relevance of “quantum error correction” to other parts of physics. Before I would answer, he added that, this is a scientific question, and he attests to the holiness of “whatever” a theoretical physicist might do and like to do.
Happily my supervisor saved me [and himself] by pointing the relevance and novelty of decoherence as a process in solid state’ and optics.