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Realisation of arbitrary controlled quantum gate

I am interested if there's some known approach when constructing quantum gates out of universal set. I was trying to construct Controlled Z gate (gate that will apply pauli-Z gate on the target qbit ...
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What are the “other” Hadamard matrices?

The Pauli matrices $$X = \begin{pmatrix}0&1\\1&0\end{pmatrix}, Y=\begin{pmatrix}0&-i\\i &0\end{pmatrix},\,\text{and}\, Z=\begin{pmatrix}1&0\\0&-1\end{pmatrix}$$ can be used ...
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Bell State vs. Bell Measurement

What is the difference between a Bell state and a Bell measurement? I am studying quantum computation, and Bell states have been introduced. I understand that Bell states can be prepared using the ...
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Information retrieval from a database

Consider a database $\cal D$ containing $N$ entries $A_0, A_1, ... A_{N-1}$, which are some fixed and unknown strings of $k$ bits; you can access this database sending a coherent superposition of ...
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What is a good book for quantum mechanics and quantum computation? [duplicate]

I am looking for a book in quantum computers for self-learning.The kind of book that teaches quantum-mechanics + quantum-computation. I have basic understanding in calculus , linear-algebra (like ...
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Tensors of rotations about an arbitrary vector in C^2

I'm trying to solve the following equation: $$e^{-i\theta/2 \sigma_{\vec{i}}^A} \otimes e^{-i\theta/2 \sigma_{\vec{i}}^B} |\Psi\rangle_{AB} = e^{i\phi} |\Psi\rangle_{AB}$$ where $e^{i\phi}$ should ...
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A question on quantum computing and de Broglie's pilot wave theory

I don't know much about quantum computing except what I have read about on wiki and popsci. I have been reading about the de Broglie-Bohm pilot wave theory and how they describe quantum mechanics in ...
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Eigenvalue of the adiabatic Hamiltonian of Farhi's three qubit 2-SAT problem

I was trying to reproduce example 3.3 of Quantum Computation by Adiabatic Evolution by Edward Farhi et. al. This is an adiabatic algorithm to solve an instance of three qubits 2-SAT problem. I think ...
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What math do I want to focus on for 1) quantum computing and 2) quantum physics? [closed]

What math do I want to focus on for 1) quantum computing and 2) quantum physics? I am interested in studying quantum computing and the Higgs Boson (quantum physics?) and ultimately working in some ...
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Scalable quantum computation vs Uncertainty Principle

tl;dr. : If we want the result of a quantum computation to have scalable more bits, we will need inner measurements to have scalable precision, if we already know the result of the computation (from a ...
145 views

Quantum computing and ambiguity

I do a bit of hobby programming and I often search the internet for little oddities that are fun to ponder over. I have read a few passages that try to explain quantum computing to the layman like ...
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Is the subadditivity of quantum entropy valid in the infinite-dimensional case?

Does the subadditivity (and strong subadditivity) of quantum entropy hold for infinite dimensional quantum systems as well? Unfortunately the books in my hand give proof for finite dimensional cases ...
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How can a qubit superposition state be written to a quantum register? [duplicate]

If a 3 qubit register can simultaneously store all 8 possible values in superposition, then how it is achieved to write 8 values in to the register? And How these 8 values can be processed parallel to ...
2k views

How are physics and computer science getting united? [closed]

How is theoretical computer science getting united with physics? Phenomena like Quantum Computing uses Quantum Mechanics to be able to compute things, how are computers helping not just to model our ...
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Approaches to Fault tolerant quantum computation

What are the various approaches to fault tolerant quantum computation ? Two examples are 1. topological quantum computation which uses topological phases in quantum states (2-Dimensional for non-...