6,119 reputation
1643
bio website jfitzsimons.org
location Singapore, Singapore
age 32
visits member for 3 years, 11 months
seen Dec 6 '13 at 16:11

I have just moved to the Center for Quantum Technologies in Singapore, after spending the last 3 years as a Merton College JRF in Theoretical Physics and a Senior Research Fellow in Oxford University Department of Materials. My research focuses largely on theoretical aspects of quantum information processing. In particular I am interested in spin networks, measurement based computation, cryptography and computational complexity.


Sep
16
answered Does entropy measure extractable work?
Sep
16
comment SuperHiggs Mechanism on different Backgrounds & Compactifications
It seems a very interesting question. I was hoping someone would be able to give you a definitive answer.
Sep
16
comment Quantum computing and quantum control
@Kaveh_kh: Perhaps you should post an answer then. For me, I see the obvious connection between circuit complexity and optimal control, but thought this was essentially to obvious to mention explicitly, and I saw the adiabatic algorithm as the deepest connection, but perhaps there is a better answer. I make no claim that this is definitive.
Sep
15
comment Quantum computing and quantum control
@Kaveh_kh: I didn't think this was the type of thing. I meant to give him an idea of some of the areas where the two intersect, not provide an exhaustive list. CW was massively overused in the early days of CSTheory and it led to problems later on, so I'm reluctant to use it too often.
Sep
15
comment Quantum computing and quantum control
To whoever downvoted, would you mind leaving a comment as to why? It helps people improve their answers, realise a mistake, etc. and is generally the constructive thing to do.
Sep
15
answered Why isn't the Gear predictor-corrector algorithm for integration of the equations of motion symplectic?
Sep
15
comment Quantum computing and quantum control
@Aaron: No problem. Hope there is something useful in this for you. The adiabatic stuff is hot at the moment, but tricky to prove anything useful.
Sep
15
answered Quantum computing and quantum control
Sep
15
comment Can symmetry generators be used for quantization?
A symmetry gives you a set of eigenstates, which is a step in the right direction, but you also need to be able to determine their corresponding eigenvalues, and a single generator doesn't do that.
Sep
15
comment Is there a Majorana-like representation for singlet states?
@UGPhysics: I don't think his question is specific to Markham's paper, but rather he gives it as an example. The Majorana representation was already in existence prior to that paper.
Sep
15
answered Is there a Majorana-like representation for singlet states?
Sep
14
comment Given a terrain, how to draw the stream flow path?
@mbq: Yep, that's close, but you need to keep removing kinetic energy from the ball.
Sep
14
comment Given a terrain, how to draw the stream flow path?
It depends. You can come up with very complicated terrain where fast flow means that the water may not take the most direct route to the bottom. You can even make water jump a gap (think urination, sorry for the crude example). However, if you can work in the limit of low slow flow then you can essentially take the steepest descent, with local minima being exited be the lowest gap (i.e. they fill up until they can't fill up any more). This is much simpler to calculate. It is also easy to verify that your assumption of slow flow was valid once you do have the path.
Sep
13
comment Theoretical Physics - How to?
@ptomato: I don't think it is at all reasonable to assert that theorist "who think they can be a good theoretical physicist with a background in pure mathematics, are not well-rounded enough to be good physicists." In fact, it seems trivial to find counter examples.
Sep
13
comment Theoretical Physics - How to?
@ptomato: Of course I don't think that's all they do, but experimental physics is fundamentally different from theoretical physics. They are distinct subjects, and while there are some people who are good at both, they are few and far between. You are asserting that experimentalists need to know differential geometry, but the fact is that most don't know any, and with good reason. It is simply not relevant to whatever they are working on. Similarly, theoretical physicists often come from purely mathematical backgrounds, and are unfamiliar with many experimental techniques.
Sep
13
comment Theoretical Physics - How to?
@ptomato: If they trying to seal a vacuum chamber? Sure. It's simply not relevant to that specific task. Very few experimentalists will have ever studied differential geometry, or example, but it is absolutely fundamental to much of theoretical physics.
Sep
13
awarded  Necromancer
Sep
13
comment What can the D-Wave quantum computer do?
@Jus12: Yes, I know. I just thought I should point out that the statement needed is slightly stronger.
Sep
13
revised What can the D-Wave quantum computer do?
added 169 characters in body
Sep
13
comment Size of a quantum computer to effectively calculate macroscopic reality from quantum mechanics
This answer is incorrect and tries to violate the Holevo bound. From an $n$-qubit system, you can at best extract $n$ bits.