Questions concerning computations performed on a quantum-computer. DO NOT USE THIS TAG just because the question concerns a computation of a quantum-system!
3
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1answer
148 views
Studying Feynman articles nowadays
I'm curious to know if it's useful to study Feynman article "Quantum Mechanical Computer" nowadays.
I'm a computer scientist, and i don't know any of the literature in quantum computers. Since long ...
3
votes
1answer
395 views
Size of a quantum computer to effectively calculate macroscopic reality from quantum mechanics
Assuming the correctness of QM: Would the size of such a computer be smaller than the observable universe? If it were to represent all available information in the universe it seems that it's minimal ...
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0answers
57 views
fixed input qubit state to an arbirary pure state using two variable rotations and one fixed rotation
It is a theorem that any arbitrary unitary transformation in SU(2) can be factored into the following form:
$ O = U_X(\theta) U_Y(\phi) U_X(\delta) $
Where $U_X$ is a Bloch sphere rotation. I ...
3
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0answers
87 views
What can quantum adiabatic computation provably accomplish?
Let's say I have a quantum adiabatic computer in a black-box that works perfectly, doesn't suffer from decoherence/noise problems, etc. Are there any proven bounds for an adiabatic algorithm that ...
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0answers
49 views
Efficiently distinguishing mixed quantum states?
Assume we know two different mixed states, p and q, and an efficient (quantum) algorithm for creating such two. Does it follow that there exists a computationally efficient method/measurement for ...
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0answers
45 views
Commutating Annihilators with a beamsplitter
I am reading Nielsen and Chuang on P. 291, for anyone interested in the origin of my question.
Given an annihilator a and its corresponding creator a_adj such that [a,a_adj] = 1 and another ...
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0answers
46 views
Looking for description of Helstrom's measurement
I hope someone can help me find the page or chapter where Helstrom discusses his famous measurement for distinguishing between two mixtures in the textbook Quantum Detection and Estimation Theory.
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0answers
110 views
Quantum circuit decomposition
I need to construct a universal quantum circuit decomposition for a three-qubit operation where one qubit is the control bit, and a two-qubit unitary operator acts on the other two
depending on the ...
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0answers
22 views
Constructing a Toffoli gate from CNOT and single-qubit gates
Toffoli gate in terms of CNOT and single-qubit gates.
Thanks much!
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0answers
24 views
The physical implementation of quantum annealing algorithm
From that question about differences between Quantum annealing and simulated annealing, we found (in comments to answer) that physical implementation of quantum annealing exists (D-Wave quantum ...
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0answers
19 views
Finding all marked element by Grover search(not in superposition)
Quantum search enables square-sped up search for marked element. When there are multiple maked element, grover search provides only superposition of them. If I want to find all the marked elements, ...
