1,524 reputation
426
bio website
location
age
visits member for 3 years, 8 months
seen Aug 24 at 0:11

delete me


Aug
23
comment Standard references in (holographic) entanglement entropy literature (Part 1)
Thanks! May be you can help with the references for the rest too?
Aug
23
comment Standard references in (holographic) entanglement entropy literature (Part 1)
You know what is the reference to this?
Aug
23
comment Standard references in (holographic) entanglement entropy literature (Part 1)
S_A is the entanglement entropy of the subsystem A.
Aug
23
asked Standard references in (holographic) entanglement entropy literature (Part 1)
Jul
21
asked Representation theory and the Nekrasov partition function
Jul
18
awarded  Nice Question
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
I think the issue is as to what do you mean by "measuring in the computational basis". What is this? This is what is forcing the collapse into the $\psi_b$ states. This would make sense only if the measurement is by an operator for whom the $\psi_b$ are the eigenstaes.
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
That $\psi_a$ is a linear combination of the $\psi_b$s can't be the reason why the wave-function collapses into only the $\psi_b$ states! One could have as well chosen a different basis to expand the $\psi_a$s in and gotten a different result!
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
CLARIFICATION : But the probabilities don't add up rightly either $\sum_b ( \bar{\psi_b} \psi_a )^2 = 2$. Wonder is the interpretation of the fact that the probabilites over all these possibilities seem to add up to $2$!
Jul
12
revised Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
added 12 characters in body
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
Also These $\psi_b$s do NOT seem to have this property that they are able to span the entire Hilbert space. They are not a basis. The probabilities don't add up either $\sum_b ( \bar{\psi_b} \psi_a )^2 = 1/2$ Then it becomes more unclear as to why you think something which is not of the $\psi_b$ will not be observed.
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
(1) So is this measurement measuring a certain observable/(Hermitian operator) whose eigenstates are theses $\psi_b$s? Then that makes perfect sense that the observation is one of these $\psi_b$s. (to give an alaogy given a spin 1/2 if one measures its spin in the x direction then its no surprise that one would get either the $|1/2,(1/2)_x>$ or $|1/2,(-1/2)_x>$ state) (2) Can you explain what is a "computational basis"? What do you mean by "measurement on the second register is made in the computational basis" ?
Jul
12
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
Clarification : I mean that the observation could have collapsed it to may be any of the vectors in this $2^{2n}$ dimensional vector space. But then why are these $\psi_b$s special? Is this observation by an operator such that $\psi_b$s are its eigenstates? Then that would make sense.
Jul
11
comment Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
Seems my question isn't clear. This particular $\psi_b$ in my question is not the only state in the Hilbert space of these two qubits. If I understand the notation correctly then the first qubit can be in any of the $|i>$ states of which there are $2^n$ of them and the second qubit can be in any of the $|x_i>$ states of which there are $2^n$ of them. So there are $2^{2n}$ states available in this Hilbert space of these 2 qubits. Then why do we think that states of only this $\psi_b$ type will be measured?
Jul
11
revised Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
deleted 108 characters in body
Jul
11
asked Why does a measurement on one qubit force another one into a given state in Simon's algorithm?
May
12
awarded  Popular Question
Apr
22
awarded  Popular Question
Mar
1
awarded  Autobiographer
Dec
22
awarded  Yearling