What is the world's biggest Schrodinger cat? How big is it by a truly quantum measurement?
I am thinking of comparing Science magazines "Breakthrough of the Year"  (BYOT) with the Zeilinger buckyball. 
The BYOT is a piezoelectric mechanical oscillator (PO) the size of the cross section of a human hair.
It is placed in a superposition of its ground state and its first excited state.
The well known buckyball experiment is a two slit experiment using buckyballs.
(A third candidate might be a macroscopic Josephson junction oscillator conducting both ways at once.)
I have made some basic calculations.
For instance, the BYOT contains about 10^14 atoms compared to 60 or 72 atoms in the buckyball.
By this measure the BYOT is bigger by a factor of about 10^12.
On the other hand, the two slits are separated by 50 to  100 nanometers, or 10^-7 meters. 
In its first excited state, the top of the BYOT PO moves about 10^-15 meters per cycle, according to my calculations.
By this measure the buckyball wins by a factor of about 10^8. 
Calculating energy of the moving parts, I find a much closer horserace, but the buckyball is about 100 times bigger.
However, none of these calculations is at all quantum mechanical (QM).
ArXiv lists at least five papers proposing truly quantum mechanical measures of the size of a macroscopic Schrodinger cat.
The most recent is Lee and Jeong http://arxiv.org/abs/1101.1209 which references the other four.
Can someone competent (or expert) in QM apply one or more of these quantum measures to the BYOT and the buckyball and tell me which is larger?
TIA. Jim Graber
 A: The largest genuine "cat state" sort of experiment I could find, measured by number of particles, was a couple of experiments on superconducting junctions which involved a few billion electrons. I have, of course, misplaced the references, but I believe this arxiv paper is one of them. (Though looking around for the reference also turns up this recent paper arguing the number is far smaller, at most a few thousand.
Note also that the "Breakthrough of the Year" paper (this Nature article) does not actually claim to have made a Schroedinger cat state. They have cooled a mechanical resonator to its ground state, and demonstrated some control over its state, but they haven't done all the work that would need to be done to demonstrate that what they have is a cat state (which would probably involve some sort of interference effects, that being the usual way to demonstrate something being in more than one state). Given what they have done, it's not a big stretch to think that they will eventually do the cat state experiment, but they haven't published that yet.
A: There has just been a paper published on the Arxiv, Matter-wave interference with particles selected from a molecular library with masses exceeding 10000 amu (summary here), that reports the current record as of November 2013.
The authors have made roughly spherical polymers of molecular weight about 10,000 by tacking fluorinated side chains onto a porphirin core, and they've managed to observe an interference pattern in a Young's slits experiment.
A: Recall that the LIGO noise limit in some frequency bands is given by the Heisenberg position uncertainty of the two multi kg single crystal sapphire mirrors, apparently about 10^-18m.  In other words, to lower the noise, the designers are planning to increase the mass of the mirrors from 10 to 40 kg apiece!  This is different from the radiation pressure uncertainties which apparently dominate the error budget in other frequency bands.   See e.g. elmer.tapir.caltech.edu/cajagwr/pdf/chen.pdf, for several examples of entanglement, squeezing, etc.   Check out the first slide for a photo of one of the 10 kg mirrors.   To see Heisenberg position uncertainty in an object of this scale is, to me, somehow truly inspiring.
A: The Dec 17 2011 Science has in its breakthrough of the year a discussion of “The first Quantum Machine.”  It is a vibrating device which has some superposition of vibrational states.  It is a maybe a sort of Schrodinger cat state.
A: I think you're all scratching your heads for nothing, how would you analyze a cat state if the theory is that you can have multiple possible outcomes before observation? Then there's the fact that if you put a clock in a box instead of a cat and the clock is synchronized with a clock outside the box, wait awhile and open the box it will always have the sametime, the synchronized time, so to say that hidden things have multiple outcomes simply because they are hidden is crazyness. The same probabilities will happen whether observed or not.
A: Dirac answers this question clearly on the superposition page--
www.enotes.com/topic/quantum_superposition. The issue is not "multiple possible outcomes before observation"--- all possible outcomes exist simultaneously, the one that materialises is the most probable one in terms of your observation, decision or measurement. A simple example from the everyday classical world is as follows--I might look at the refrigerator, and  decide it might stop working because it is making a buzzing noise, I might then decide its not level, so I go and get the spirit level and level it----this is the outcome of me looking at the refrigerator but before I make a decision there is an infinite number of ways I could look at the refrigerator, I could decide I need a beer, so I go to the refrigerator and get a beer... ect., ect., ie I could decide many other things related to the refrigerator.
Some people call this "the collapse of the wave function" ie there are an infinite number of
wave functions existing between me and the refrigerator, but the wave function eventually collapses into a single wave function once I make a decision or measurement. The single wave function is my action, or observation.
This has profound metaphysical implications, if thought about deeply.
We're in good company---Einstein also posed the question "do you really believe that the moon does not exist when you are not looking at it?"--Einstein is here referring to the "superposition principle", later defined clearly by Dirac. albeit somewhat mathematically, ie the moon exists in an infinite variety of states until observed or measured. Bohr's reply to Einstein on such issues was--
"Einstein, do not tell God what to do"--see Bohr-Einstein letters, or Wikipedia page 
"Bohr-Einstein debates".
