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Clifford gates are transversal What exactly does this transversal mean? What is the difference between non-Clifford gates and Clifford gates?
Clifford gates are transversal What exactly does this transversal mean? What is the difference between non-Clifford gates and Clifford gates? Why is it simple for Clifford gates to implement transversal for quantum fault tolerance? Please explain…
Wang
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Implementation of the oracle of Grover's algorithm on IBM Q using three qubits
I am trying to get used to IBM Q by implementing three qubits Grover's algorithm but having difficulty to implement the oracle.
Could you show how to do that or suggest some good resources to get used to IBM Q circuit programming?
What I want to do…
Bick
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Review paper on depth, qubits and $T$ gates number on Clifford+T decomposition for various "typical" algorithms
My question
I am looking for some review paper, or a list of different papers providing concrete numbers about the depth, number of qubits and number of $T$ gates required on the Clifford+T basis for usefull quantum algorithms (quantum Fourier…
Marco Fellous-Asiani
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Grover's algorithm: what to input to Oracle?
I am confused about what to input to Oracle in Grover's algorithm.
Don't we need to input what we are looking for and where to find what we are looking for to Oracle, in addition to the superpositioned quantum states?
For example, assume we have a…
Bick
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11
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Why is an oracle qubit necessary in Grover's algorithm?
I am a bit confused about the necessity of an oracle qubit in Grover's algorithm.
My question is, does it depend on how you implement your oracle whether you need an oracle qubit or not? Or, it there any reason for an oracle qubit? (such as, there…
Bick
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11
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2 answers
AWS Braket Backend for Qiskit?
Is there a working AWS Braket backend provider for Qiskit 0.29 that can be used with the MinimumEigenOptimizer interface? The qiskit-aws-braket-provider package is unfortunately not working.
Nepomuk Hirsch
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Is Qiskit more popular than cirq? Why?
It seems like most people are using Qiskit, what's the difference?
nighthawk30
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11
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Devising "structured initial guesses" for random parametrized quantum circuits to avoid getting stuck in a flat plateau
The recent McClean et al. paper Barren plateaus in quantum neural network training landscapes shows that for a wide class of reasonable parameterized quantum circuits, the probability that the gradient along any reasonable direction is non-zero to…
Daniel Yaacov
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Are there any quantum software startups?
I am aware of the quantum hardware startup Rigetti and I wonder if there are any quantum startups that build software on top of current quantum computer hardware for commercial applications?
Related question: Does a complete list of open quantum…
QNerd
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How is Grover's algorithm used to estimate the mean and median of a set of numbers?
On the Wikipedia page for Grover's algorithm, it is mentioned that:
"Grover's algorithm can also be used for estimating the mean and median of a set of numbers"
So far I only knew how it can be used to search a database. But not sure how to…
Sanchayan Dutta
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What are the real advantages of superdense coding?
In superdense coding, two qubits are prepared by Eve in an entangled state; one of them is sent to Alice and the other is sent to Bob. Alice is the one who wants to send (to Bob) two classical bits of information. Depending on what pair of classical…
user72
11
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2 answers
Quantum Chemistry and Quantum Computing
Predicting the energy of molecules to high accuracy during the course of a chemical reaction, which in turn allows us to predict reaction rates, equilibrium geometries, transition states among others is a Quantum Chemical problem.
Quantum Computing…
user3483902
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Does the symmetric logarithmic derivative operator have a geometric interpretation?
In the context of Bures metric and quantum Fisher information, an important object is the symmetric logarithmic derivative (SLD). This is usually introduced as a way to express the derivative of a parametrised state as a superoperator acting on the…
glS
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Who was the first to call the phase gates $P(\pi/2)$ and $P(\pi/4)$ the $S$ and $T$ gates, and were they motivated by generators of the modular group?
Within the theory of quantum gates, a common pair of single-qubit phase gates are the $P(\pi/2)=S$ and $P(\pi/4)=T$ gates, with
$$S= \begin{bmatrix} 1 & 0 \\ 0 & i \end{bmatrix},\:T = \begin{bmatrix} 1 & 0 \\ 0 & e^{i \frac{\pi}{4}}…
Mark Spinelli
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Minimum number of T gates needed to perform two overlapping Toffolis
Consider this circuit:
How many T gates are needed to implement it, in the stabilizer+T gate set? The circuit can use cliffords, measurement, classical feedback, ancilla qubits, and T gates. Only T gates cost.
I know how to do it with 8 T gates,…
Craig Gidney
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