Here's a link to the paper referenced in the excerpt:

**Direct measurement of a 27-dimensional orbital-angular-momentum state vector**

ABSTRACT: The measurement of a quantum state poses a unique challenge for experimentalists. Recently, the technique of \direct measurement" was proposed for characterizing a quantum state in-situ through sequential weak and strong measurements. While this method has been used for measuring polarization states, its real potential lies in the measurement of states with a large dimensionality. Here we show the practical direct measurement of a high-dimensional state vector in the discrete basis of orbital-angular momentum. Through weak measurements of orbital-angular momentum and strong measurements of angular position, we measure the complex probability amplitudes of a pure state with a dimensionality, d=27. Further, we use our method to directly observe the relationship between rotations of a state vector and the relative phase between its orbital-angular-momentum components. Our technique has important applications in high-dimensional classical and quantum information systems, and can be extended to characterize other types of large quantum state.

(it's an 8-page pdf file)

http://arxiv.org/pdf/1306.0619.pdf

Some related background info...**Answer: **Quantum entanglement is one of the central principles of quantum physics, though it is also highly misunderstood. In short, quantum entanglement means that multiple particles are linked together in a way such that the measurement of one particle's quantum state determines the possible quantum states of the other particles.
### The Classic Quantum Entanglement Example

### The Wavefunction of the Universe

##### Quantum Entanglement Articles

**Question: **What is Quantum Entanglement?

The classic example of quantum entanglement is called the EPR paradox. In a simplified version of this case, consider a particle with quantum spin 0 that decays into two new particles, Particle A and Particle B. Particle A and Particle B head off in opposite directions. However, the original particle had a quantum spin of 0. Each of the new particles has a quantum spin of 1/2, but because they have to add up to 0, one is +1/2 and one is -1/2.

This relationship means that the two particles are entangled. When you measure the spin of Particle A, that measurement has an impact on the possible results you could get when measuring the spin of Particle B. And this isn't just an interesting theoretical prediction, but has been verified experimentally through tests of Bell's Theorem.

One important thing to remember is that in quantum physics, the original uncertainty about the particle's quantum state isn't just a lack of knowledge. A fundamental property of quantum theory is that prior to the act of measurement, the particle really *doesn't have* a definite state, but is in a superposition of all possible states. This is best modeled by the classic quantum physics thought experiment, Schroedinger's Cat, where a quantum mechanics approach results in an unobserved cat that is both alive and dead simultaneously.

One way of interpreting things is to consider the entire universe as one single wavefunction. In this representation, this "wavefunction of the universe" would contain a term that defines the quantum state of each and every particle. It is this approach that leaves open the door for claims that "everything is connected," which often gets manipulated (either intentionally or through honest confusion) to end up with things like the physics errors in *The Secret*.

Though this interpretation does mean that the quantum state of every particle in the universe affects the wavefunction of every other particle, it does so in a way that is only mathematical. There is really no sort of experiment which could ever - even in principle - discover the effect in one place showing up in another location.

2 posted on **01/22/2014 2:54:08 PM PST** by ETL
(ALL (most?) of the Obama-commie connections at my FR Home page: http://www.freerepublic.com/~etl/)

To: **BenLurkin; Zeneta; Moose Burger; piytar; FredZarguna; Chode; DaveMSmith; E. Pluribus Unum; ...**

Quantum Mechanics ping.

If you’d like on or off this list, please let me know.

4 posted on **01/22/2014 2:55:07 PM PST** by ETL
(ALL (most?) of the Obama-commie connections at my FR Home page: http://www.freerepublic.com/~etl/)

To: **Slings and Arrows; Revolting cat!; Daffynition**

Final exam question: Does Schrodeinger’s cat box need cleaning?

7 posted on **01/22/2014 3:04:13 PM PST** by a fool in paradise
("Health care is too important to be left to the government.")

To: **ETL**

As the German physicist Werner Heisenberg first pointed out in 1927, taking a **measurement** of one state, say, the electron's position, and you irreversibly alter its momentum, and vice versa. In the parlance of quantum physicists, the "wavefunction" of a system's probabilities "collapses" into a specific state when you **observe** it.

stooopid question #1, i understand how actually measuring/metering could alter an objects state, but... how can observing it(under the assumption it means with your eyes) change it's state???

or is he using the words interchangeably?

15 posted on **01/22/2014 3:15:16 PM PST** by Chode
(Stand UP and Be Counted, or line up and be numbered - *DTOM* -vvv- NO Pity for the LAZY - 86-44)

To: **ETL**

If they can’t see the inherent contradiction in saying that something exists simultaneously in two contradictory states, then no power on Earth can help them.

19 posted on **01/22/2014 3:17:53 PM PST** by I want the USA back
(Media: completely irresponsible traitors. Complicit in the destruction of our country.)

To: **Physicist**

Just curious if you are still around. I used to enjoy your post’s on “science” threads (unlike what has become of them these days)...

20 posted on **01/22/2014 3:18:52 PM PST** by Ghost of SVR4
(So many are so hopelessly dependent on the government that they will fight to protect it.)

To: **ETL**

29 posted on **01/22/2014 3:36:52 PM PST** by skinkinthegrass
(The end move in politics is always to pick up a gun..0'Caligula / 0'Reid / 0'Pelosi)

To: **ETL**

Penny proved that Schrodeinger’s cat is alive.

To: **ETL**

To: **ETL**

this description reminds me of manuevring board solutions when doing shipboard operatons - using vectors on speed and position measurement to determine future states of speed and position

79 posted on **01/22/2014 10:19:32 PM PST** by reed13k
(For evil to triumph it is only necessary for good men to do nothings)

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