# All Questions

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### From Qubo Hamiltonian to Ising Hamiltonian

I would like to convert my qubit hamiltonian fom the HeH+ system that I have obtained using Qiskit to an Ising or QUBO model. I have seen multiples examples from QUBO to Qubit Hamiltonian but on the ...
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### Diamond distance and channel coding - connection?

Let us consider an encoder, noisy channel and decoder such that classical messages $m\in\mathcal{M}$ can be transmitted with some small error. That is, for a message $m$ that is sent by Alice, Bob ...
11 views

### How does the amplitude amplification in Grover's algorithm work?

As the question says - how does the amplitude amplification in Grover's algorithm work? I am fine with adding the negative phase on the winning state, but how does one generate the diffuser to ...
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### Initial state for QAOA

I'm learning about QAOA and I got curious about how they choose initial state. They somehow decided to choose initial state as equal superposition of all possible state and I wonder that there is any ...
54 views

### How do you change the backend.run() command?

This is code from Chapter 6.1 of the qiskit textbook, which shows a job being run. How would you change the first line of the backend.run() command, the schedules parameter, in order to use it for a ...
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### Integer factorization using Shor's Alorithm

I have question about Shor's algorithm, from I know it's for factorize an integer and can factorize big number with ease. I using Qiskit to try make a simple factorization program (with local ...
31 views

### Increasing entropy for projective LCPT mapping

Given a set of projectors $\{P_i\}$ acting on a space $\mathcal H_S$, let $\Phi$ be the LCPT map defined by $$\Phi(\rho)=\sum_i P_i\rho P_i.$$ The goal is to show that $S(\Phi(\rho))\ge S(\rho)$. The ...
31 views

### Vector math of applying an X-gate on an $|i\rangle$ basis state

It is well known that the X-gate will apply a rotation about the x-axis on the bloch sphere. Knowing this, the $|i\rangle$ state should be converted to the $|-i\rangle$ state on the application of ...
29 views

### Comparing technical limitations of major quantum computing approaches

As far as I know, major quantum computing approaches include superconducting qubits, trapped ions, nuclear magnetic resonance qubits, and free space quantum optics. I guess two main technical ...
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### Question about the counter diabatic(CD) term in Digitized Adiabatic Quantum Computing

Recently I have read two articles about the Digitized Adiabatic Quantum Computing(DAQC), and tried to factorize $35=5\times7$ and $2479=67\times37$. But some problems came when trying to solve the ...
43 views

### How to determine the direction of arrows on a Bloch sphere from a vector/ket representation?

The following graphs contain the vector/ket representation of the vector on the bloch sphere. I don't understand how to determine the position of the vector on the bloch sphere based on those vector/...