Posted, without comment:
quant-ph/0606017 [abs, ps, pdf, other] :
Title: Can measuring entanglement be easy?
Authors: S.J. van Enk
Comments: No
My Dream Scam
Gordon Watts over at Life as a Physicist describes a cool response to (crank) manuscripts purporting to factor large numbers (via The Old New Thing). This reminds me of a scam I once dreamed up. The scam would consist of an email like the one here:
Dear sir or madam!
In today’s modern world, an increasing amount of the world’s commerce is performed over the internet. Most people believe that such financial transactions over the internet are perfectly secure. They do not hesistate to send their credit card over “so-called” secure connections because they have been told by computer scientists that such transactions are secure. But are these transactions really secure? The main reason for the claims of security for these transaction is “that it is hard to factor large numbers?” But why should it be hard to factor large numbers. Certainly my computer can multiply large numbers very rapidly!
Recently, I was pondering this question with deep thought and it occured to me that indeed, rapid factoring of large numbers is indeed possible. In a brilliant flash of insight I have develope a new and revolutionary method for factoring large numbers. Thus I can break the codes used to protect your credit card transactions. That’s right: I can steal money from you the next time you use the internet. Now, I wouldn’t want to do this to you, an anonymous person who I am sure is a law abiding citizen. However, the U.S. patent office will not allow me to patent my algorithm for factoring. Thus I, the great discoverer of an amazing new algorithm will go away from my invention penniless. That’s not how capitalism is supposed to work is it. Thus I am willing to make the following deal with you. If you want to securely use your credit card over the internet again, I am willing to offer you protection from my algorithm for factoring large numbers. The Factoring Protection Plan(TM) will provide you total security for your internet transactions. And it only costs ten U.S. dollars a month. To subscribe to this plan, please click on this link.
Of course, you may not believe that my algorithm can be used to efficiently factor large numbers. But I’m willing to share some of my results with you. For example, when I ran my program on the number
18819881292060796383869723
94616504398071635633794173
82700763356422988859715234
66548531906060650474304531
73880113033967161996923212
05734031879550656996221305
168759307650257059
my program told me that this number is the product of
3980750864240649373971
2550055038649119906436
2342526708406385189575
946388957261768583317
and
4727721461074353025362
2307197304822463291469
5302097116459852171130
520711256363590397527
Amazing, no? Do you need any more proof that your next credit card transaction will not be secure?
I hope that you will make the correct decision and decide to subscribe to my
Yours,
The trapdoor breaker
Quantum Computing Undergrad Labs
One of the cool talks at the northwest APS meeting I attend a little over a week ago was a talk by Mark Beck from Whitman college on implementing Hardy’s test of local realism in an undergraduate lab. I sure wish I’d had this lab when I was an undergraduate (as it is I most remember a lab in which we made a high temperature superconductor…mostly due, unfortunately, to the ungodly amount of time we spent trying to get the stuff to superconduct!) There aren’t many labs where you can get your hands on an experiment related to quantum informatino information processing, are there. In fact the only other one I know of is in the Junior lab at MIT where they do an NMR quantum computing experiment. Anyone know of any other undergraduate labs which are relevant to quantum computing?
A Visitor
For those of you local to Seattle, Scott Aaronson, keeper of the complexity zoo, will be giving a talk this Thursday:
Event: Colloquium, 05/25/2006 11:30 am, Gates Commons, CSE 691
Speaker: Scott Aaronson (University of Waterloo)
Talk: The Learnability of Quantum States
Abstract: Using ideas from computational learning theory, I’ll show
that “for most practical purposes,” one can learn a quantum state
using a number of measurements that grows only linearly with the
number of qubits n. By contrast, traditional quantum state tomography
requires a number of measurements that grows exponentially with n.
I’ll then give two applications of this learning theorem to quantum
computing: first, the use of trusted classical advice to verify
untrusted quantum advice, and second, a new simulation of quantum
one-way protocols.
Even though there exists an algorithm to “learn” a quantum state after
a small number of measurements, that algorithm might not be efficient
computationally. As time permits, I’ll discuss ongoing work on how to
exploit that fact to copy-protect and obfuscate quantum software
Holy Grails
From article entitled “Bright Outlook for Queenland Nanotechnology Alliance”:
…their efforts are focused on making a significant impact into solving many of the holy grails, such as clean energy, personalised medicine and quantum computing.
Well I’m not sure if quantum computing is a hoy grail, but I’m pretty sure quantum computing researchers all know and laugh at “The Holy Grail.”
$-Wave
Okay, we will officially call this week “D-wave week.” According to an article here (update: for a link that may work for all browsers, see here), D-wave just secured another round of financing, to the tune of $14,000,000.
Topological Phases and Quantum Computation
The KITP is hosting a conference on Topological Phases and Quantum Computation which starts today. The talks should be appearing online this week here. Wish I could be there, but hopefully most of the talks will appear online, thus allowing the teaching bound like me to follow the conference from afar.
Quantum Computing for Undergrads?
Lately I have been pondering how I would teach quantum computing to computer science undegraduates. Imagine the class was made up of juniors and seniors who are majoring in computer science or computer engineering. How would you teach such a class?
My first thought is that I would attempt to structure the class more around programming and simulating quantum circuits than on the more abstract course that one normally sees in quantum computing. Certainly this would have the advantage of stressing the students previous strengths (leaving out, unfortunately, the theory students. But if they are really destine to be theory students they should try to take the graduate level course, no?) It would also give them hands on access to the abstract ideas of quantum computing. What I’d really like to use for this would be somethign akin to a hardware description language combined with a simulation synthesis tool. It would also be awesome if a CAD tool could also be developed. However, I haven’t seen anything quite resembling this in the quantum simulation world, but I’d certainly be happy to find out if such programs exist.
Depth or Breadth?
Which would you rather have, breadth or depth? Suppose I give you the choice between the following two directions in experimental research in quantum computing in the next five years: either a few (say ten to thirty) qubits with extremely low decoherence and high control precision (perhaps even a high enough to perform quantum error correction) or a huge number of qubits (say hundreds to thousands to millions) with fairly poor decoherence and control. Assume that in both cases, fabrication can be done with a fairly high degree of sophistication. Of of these two options, which would you perfer to see in the near future?
D-Wave News
D-Wave Systems, those crazy Vancouverites trying to build a quantum computer, have a new CEO:
VANCOUVER, BRITISH COLUMBIA, May 9 /CNW/ – D-Wave, developer of the world’s most advanced computers, has appointed Silicon Valley technology executive and entrepreneur Herbert J. Martin as chief executive officer.
Which makes me dream of the day when I will be able to include in my grant proposal a request for dollars to buy a quantum computer.