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Significance of The Church of the Higher Hilbert space
The term "Church of the Higher Hilbert Space" is used in quantum information frequently when analysing quantum channels and quantum states.
What does this term mean (or, alternately, what does the term "Going to To the Church of the Higher Hilbert…
user3483902
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22
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3 answers
Advantage of quantum key distribution over post-quantum cryptography
Post-quantum cryptography like lattice-based cryptography is designed to be secure even if quantum computers are available. It resembles currently employed encryptions, but is based on problems which are most likely not efficiently solvable by a…
M. Stern
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What is the intuition behind quantum t-designs?
I started reading about Randomized Benchmarking (this paper, arxiv version) and came across "unitary 2 design."
After some googling, I found that the Clifford group being a unitary 2 design is a specific case of "Quantum t-design."
I read the…
Blackwidow
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Quantum states are unit vectors... with respect to which norm?
The most general definition of a quantum state I found is (rephrasing the definition from Wikipedia)
Quantum states are represented by a ray in a finite- or infinite-dimensional Hilbert space over the complex numbers.
Moreover, we know that in…
Adrien Suau
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Density matrices for pure states and mixed states
What is the motivation behind density matrices? And, what is the difference between the density matrices of pure states and density matrices of mixed states?
This is a self-answered sequel to What's the difference between a pure and mixed quantum…
Sanchayan Dutta
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What integers have been factored with Shor's algorithm?
Shor's algorithm is expected to enable us to factor integers far larger than could be feasibly done on modern classical computers.
At current, only smaller integers have been factored. For example, this paper discusses factorizing…
Lying Dancer
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Why are quantum gates unitary and not special unitary?
Given that the global phases of states cannot be physically discerned, why is it that quantum circuits are phrased in terms of unitaries and not special unitaries? One answer I got was that it is just for convenience but I'm still unsure.
A related…
wdc
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Is Quantum Biocomputing ahead of us?
Now that we know of bio/molecular tools that allow living organisms to deal with quantum computations e.g. the fancy proteins that allow birds to handle quantum coherence (e.g. The quantum needle of the avian magnetic compass or Double-Cone…
AG-M
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Quantum Bitcoin Subdivision
Background
Recently I was reading the article "Quantum Bitcoin: An Anonymous and Distributed Currency Secured by the No-Cloning Theorem of Quantum Mechanics" which demonstrates how a quantum bitcoin could function. The article's conclusion states…
Daniel Burkhart
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What protocols have been proposed to implement quantum RAMs?
The crucial role of random access memories (RAMs) in the context of classical computation makes it natural to wonder how one can generalise such a concept to the quantum domain.
Arguably the most notable (and first?) work proposing an efficient QRAM…
glS
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What is the difference between a qubit and classical bit?
As I understand it, the main difference between quantum and non-quantum computers is that quantum computers use qubits while non-quantum computers use (classical) bits.
What is the difference between qubits and classical bits?
luap42
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How is quantum cryptography different from cryptography used nowadays?
Recent researches indicate that quantum algorithms are able to solve typical cryptology problems much faster than classic algorithms.
Have any quantum algorithms for encryption been developed?
I'm aware about BB84, but it only seems to be a partial…
Be Brave Be Like Ukraine
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Is my background sufficient to start quantum computing?
I am a first-year undergraduate electrical engineering student. I want to study quantum computing and quantum AI in the future and also possibly work on building quantum computers.
I have finished Strang's Introduction to Linear Algebra twice and…
Huseyin Okan Demir
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Twirling Quantum Channels: Pauli and Clifford Twirling
I am currently working through some papers related with approximations of more general quantum channels such as amplitude and phase damping channels to Pauli channels. The reason to do so is so that the Gottesman-Knill theorem is fulfilled and…
Josu Etxezarreta Martinez
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Tools for creating quantum circuit diagrams
What tools exist for creating quantum circuit diagrams and exporting them as images? Preferably one which runs in Windows, or even better one which runs in the web browser.
ahelwer
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