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Combinatorial structure of the entanglement spectrum and quantum error correction in finite vector spaces

Let $V$ be a finite-dimensional vector space over $\mathbb{C}$ with dimension $d$. Consider a subspace $S \subset V^{\otimes n}$ representing the code subspace of a quantum error correcting code. We ...
Hanz Deutch's user avatar
3 votes
1 answer
524 views

Has the von Neumann entropy ever been used in classical mechanics?

After going through an application of the von Neumann entropy(from quantum information theory) to certain problems in computational neuroscience [2], it occurred to me that this entropy might have ...
Aidan Rocke's user avatar
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6 votes
0 answers
360 views

What is the status of the Born Rule in axiomatic QM?

While physicists have tried multiple times and failed to derive the Born Rule (for example: https://arxiv.org/pdf/quant-ph/0409144.pdf). I was wondering what axiomatic Quantum Mechanics had to say ...
More Anonymous's user avatar
1 vote
0 answers
567 views

How to estimate the quantum fidelity between two given states

There is a well-known theorem, firstly obtained by Denes Petz, in quantum information theory, which is described as follows: $\mathbf{Theorem.}$ Let $\rho$ and $\sigma$ be two states on $\mathcal H$, ...
Lin Zhang's user avatar
9 votes
4 answers
2k views

Is there a useful generalization of the Schmidt decomposition to the tensoring together of 3 or more vector spaces?

I've rewritten the question in math notation, and I've left the old version in physics bra-ket notation here. Background A simple consequence of the singular value decomposition is that any vector $...
Jess Riedel's user avatar
3 votes
1 answer
632 views

What is the entropy of a density matrix which is the sum of two unitarily equivalent projectors?

Construction Suppose I have a density matrix $\rho$ which is proportional to a projector $P$ formed by tensoring together $N$ small projectors $P^{(i)}$ of rank 2: $P^{(i)} = |a\rangle_i\langle a| + |...
Jess Riedel's user avatar