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Are there any encryption suites which can be cracked by classical computers but not quantum computers?
Are there any encryption suites that can be cracked by usual computers or super computers, but not quantum computers?
If that's possible, what assumptions will it depend on? (Factorizing big numbers, $a^b\pmod d$ $a^c\pmod d$ $a^{bc}\pmod d$ etc...)
MCCCS
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Do real commercial quantum computers exist?
We have been reading about quantum computers being developed and tested in labs.
And also, we have quantum simulator programs that use limited virtual qubits (up to 30-40 qubits if cloud-based).
And we have also started learning new quantum…
Koder101
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Circuit for VQE Expectation Value Finding
I'm looking into the circuit for the VQE, but am stumped at how we can identify the expectation value of the Pauli series. Essentially, how do we find:
$$ \langle \psi | H_i | \psi \rangle $$
Given $H_i$ can be decomposed into Paulis?
The first…
C. Kang
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What is the advantage of quantum machine learning over traditional machine learning?
Why exactly is machine learning on quantum computers different than classical machine learning? Is there a specific difference that allows quantum machine learning to outperform classical machine learning?
Rob James
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What are the benefits of using quantum machine learning?
I have been investigating uses for quantum machine learning, and have made a few working examples (variations of variational quantum classifiers using PennyLane). However, my issue now is its relationship with classical machine learning. At the…
Andrew
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Procedures and intuition for designing simple quantum circuits?
I'm working my way through one of the quantum circuits sections in Nielsen and Chuang and I'm struggling to get a feel for the basics of circuit construction. For example, one of the exercises is as follows:
This exercise seems really simple on the…
Arthur Allshire
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How does evolving a two-qubit state through a CNOT gate entangle them?
Reading into CNOT gate I understand that, mathematically, such a gate entangles the control qubit and the target. (the resulting state is $\frac{1}{\sqrt 2}(|00\rangle+|11\rangle)$)
However, looking at the "truth table" of the gate, it seems as…
ItamarG3
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Preparing a quantum state from a classical probability distribution
Suppose I have a black-box unitary $U_p$ which is described as follows: given a finite probability distribution $p:\{1,\ldots,n\}\rightarrow \mathbb{R}_{\geq0}$, where $\sum_{x=1}^n p(x)=1$, the action of the black box on a basis is given by…
Condo
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Simplification of "rotation swapping" circuit
While trying to simplify a certain 2-qubit quantum circuit, I managed to get it down to this:
But by inspecting the corresponding two-qubit unitary directly, I can come up with the arguably simpler:
where the rotation operator "moved" to the first…
Andrea Olivo
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Are there any experimental groups currently measuring quantum contextuality?
I work as a theorist with my current research interests in "quantum contextuality". For those perusing the question, this is essentially a generalization of non-locality where we can show a quantum system does not admit a hidden-variable model. So…
Emily Tyhurst
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New Hybrid-HHL algorithm vs VQLS
A team of researchers has realized hybrid quantum algorithm for solving a linear system of equations with exponential speedup that utilizes quantum phase estimation, the algorithm demonstrates quantum supremacy and holds high promise to meet…
Carlos Alfredo Vergara Rojas
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Why Google has used $\sqrt{X}$ and $\sqrt{Y}$ instead of $X$ and $Y$ in supremacy experiment?
In supremacy experiment Google has used $\sqrt{X}$ and $\sqrt{Y}$ as two of their single qubit gates (paper).
So My questions are:
Is there any specific reason for choosing these gates and not $X$ and $Y$ instead?
Is it because of technical…
Ali s.k
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Is there quantum advantage to be had with a D-Wave computer in 2020?
I've seen a lot of excitement in the popular press about the computers made by D-Wave Systems, but when I dig deep the only practical things that I can figure out that one can do with the computer are variations of:
Train one's staff in the use of…
vy32
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What does it mean to take the Choi-Jamiolkowski of a quantum channel?
The Choi-Jamiolkowski of a channel $\newcommand{\on}[1]{\operatorname{#1}}\Lambda : \on{End}(\mathcal{H_A}) \xrightarrow{} \on{End}(\mathcal{H_B})$ is obtained through an isomorphism of the form:
$$
CJ:
…
the mmmPodcast
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Decomposing Hamiltonian into qubit model representation
One of the main applications of VQE is its application to find the approximation to the ground state energy (smallest eigenvalue of the Hamiltonian) for a particular molecule through an iterative method.
To be able to do this, we first need to write…
KAJ226
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