Skip to main content

All Questions

3 votes
1 answer
139 views

Is there a relation between some kind of distance and the Schmidt basis?

Consider two bipartite quantum states $|\phi\rangle^{AB}$ and $|\psi\rangle^{AB}$ (in a finite dimensional Hilbert space $\mathcal H_A\otimes \mathcal H_B$), such that $$\| |\phi\rangle\langle\phi|^{...
Takimoto.R's user avatar
1 vote
5 answers
1k views

Mathematical explanation of bra-ket notation in quantum mechanics

$\newcommand{\hp}[1]{\hphantom{#1}}$ We have the entangled state of two pairs of qubits: $$ |\psi \rangle =\frac{1}{2}|0011\rangle-\frac{1}{2}|0110\rangle-\frac{1}{2}|1001\rangle+\frac{1}{2}|1100\...
azerbajdzan's user avatar
31 votes
7 answers
7k views

What is the actual use of Hilbert spaces in quantum mechanics?

I'm slowly learning the quirks of quantum mechanics. One thing tripping me up is... while (I think) I grasp the concept, most texts and sources speak of how Hilbert spaces/linear algebra are so useful ...
Ringo Hendrix's user avatar
1 vote
1 answer
2k views

Schmidt decomposition of entangled state [closed]

I have a problem with some homework our teacher assigned. I have to find the Schmidt decomposition of the entangled state $$\lvert\psi\rangle_{A,B}=\frac{1}{2}\lvert0\rangle_{A}\lvert0\rangle_{B}-\...
Nicola Bazinga Dragoni's user avatar
6 votes
2 answers
674 views

Why is the dimension of the set separable states $\dim\mathcal H_1+\dim\mathcal H_2$?

Please can you help me to understand how the dimension of the set of separable states is $\dim \cal H_1 + \dim \cal H_2$? This is the relevant passage: So far, we have assumed implicitly that the ...
Myshkin's user avatar
  • 233