The “Bell” and “PhiPlus” states should be the same. However, in certain cases, I have found that creating these (named) states using QuantumState[] can lead to differences depending on the way the basis is specified. In fact, the “PhiPlus” state can fail to have certain properties, such as “Formula”, when it works fine for the “Bell” state. Why aren’t they always the same?
See attached notebook
for example.
Michael, the 2nd argument of QuantumState[arg1,arg2] has the information of QuantumBasis
When arg1 is already a quantum state, the meaning of QuantumState[QuantumState[…],arg2] is to transform QuantumState[…] into new basis arg2
Of course, new basis should match the dimensionality of original state QuantumState[…]
Mads, Thanks for emphasizing the fact that when arg1 is already a quantum state, the second arg2 is there to transform the state to a new basis. However, my question was really the following: Since “Bell” and “PhiPlus” are the same state, why should any result involving a call to QuantumState[] (regardless of the basis specification) be different? In other words, each of the two rows in my table should be identical, since the only difference between them is arg1 (i.e., either “Bell” or “PhiPlus”).
I do not get any error or missing. Try installing paclet again and let me know if still issues:
PacletInstall["Wolfram/QuantumFramework", ForceVersionInstall -> True]
Needs["Wolfram`QuantumFramework`"]
Oh wow! I just ran my question notebook again (without even re-installing the paclet) and it worked! It’s magic!
I sometimes have problems installing the paclet. (not always). Sometimes I have to quit the kernel and start it again and sometimes I don’t. Usually I get everything working though in one or two tries. But let’s leave that problem for another day. It’s Saturday night and time for a beer! Thanks for your help. Mike