Questions tagged [qubo]
Questions about or related to QUBO (quadratic unconstrained binary-function optimization).
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Mapping a QUBO onto an observable for use with Qiskit QAOA
Background
I am attempting to understand the post-aqua way that external qiskit libraries are supposed to be used for solving QUBOs. To do so I am trying to work with the toy problem of minimizing $f(...
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Is there a compendium of quadratic penalties for logic relationships between binary variables?
I'm looking for a compendium/look-up table for a relationship between binary variables, and corresponding QUBO penalty functions. I'm aware of a few from DWave docs, this question, but I can't find a ...
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Did D-Wave show quantum advantage in 2023?
I would like to know your thoughts on whether or not D-Wave has shown a a smoking-gun example of quantum advantage this year. I am genuinely not quite sure what to think, but I believe the answer to ...
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bad solution to the knapsack problem on Qiskit
To solve the knapsack problem, I translate it into a QUBO. But the solutions obtained on the simulator are incorrect. Are there ways to make the answers correct?
The picture shows the cost function, ...
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How to use D-Wave decomposers?
I'm currently trying to work on a minimization problem using D-Wave hybrid and quantum machines.
The problem is, shortly, an energy optimization for a network of switches and servers, linked as a ...
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How can I exactly solve a Quadratic Model with integer variables using DWave Ocean classical solvers?
As an example, let's consider the following simple QuadraticModel problem with just 3 INTEGER variables:
...
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4-cities traveling salesman quantum algorithm (QUBO)
A quantum version of the traveling salesman algorithm is discussed here:
There is a reference to QUBO, Ising, and some matrix constructions,
and the output in the end:
Is anyone able to run through ...
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How to use Warm-Start QAOA in QisKit to solve non-convex QUBO problem?
I have a non-convex QUBO problem that I'd like to solve by warm-starting QAOA with a solution obtained from a continuous relaxation solution obtained by a classical algorithm. The specifics of the ...
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Inequality constraint to QUBO penalty
I am trying to formulate a problem as QUBO problem and am not able to transform the inequality constraint.
$$ \sum_i^N x_i \geq 1 $$ into a suitable penalty function. For N = 2, the penalty term can ...
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Extracting a QUBO matrix from pyqubo
I am benchmarking different QUBO solvers for a very simple instance of the knapsack problem.
Some of these solvers require the matrix, Q, and offset, b, from the equation:
$$
\begin{equation}
x^{\...
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Grover's algorithm to maximize QUBO functions
I'm trying to maximize a QUBO function f(x,y,z) = 3xy + 4xz - 3yz + 11y + z. How can I use Grover's algorithm to do this?
I've been told to encode this cost ...
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How can a QUBO matrix with many identical, non-zero off-diagonal terms be made sparse?
I am with a QUBO matrix where entire off-diagonal sections are with the same value, which is the same between sections. Consider the following example (much smaller than those I am actually working ...
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Convert Hamiltonian to Ising Formulation or QUBO
I have a tridiagonal Hamiltonian matrix that I need to convert to QUBO or Ising format to use D-Wave's quantum annealing solvers. For a generic tridiagonal:
\begin{pmatrix}
a_1 & b_1 \\
c_1 & ...
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What are the important parameters when it comes to VQE algorithms in qiskit?
So I wrote an algorithm for a quadratic problem (qubo) and try to solve it. My question is why I don't get the correct results when running my algorithm on a quantum computer like IBM_manila. In the ...
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Penalty formulation regarding inequalitties
During the formulation of a QUBO matrix I have a question regarding penalty formulation.
Once I'm done with QUBO formulation such as $x_{i}Ax_{j}$ where A is the QUBO matrix, $x_{i}$ and $x_{j}$ are ...
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Mathematical definition of QUBO problem
The quantum annealing approach is using the equivalence between QUBO matrix and Ising Hamiltonian to solve the problem. Therefore, it is necessary to transform a NP-hard problem into a QUBO matrix. ...
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How to formulate QUBO as summation quadratic and linear parts of K-graph coloring problem?
While trying to understand the graph coloring problem with VQE using the QUBO Formulation mentioned section "5.2 Graph Coloring". Mentioned article prepared the QUBO directly in to matrix ...
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Can D-Wave machines solve QUBO problems more efficiently than gate model devices?
I'm new to quantum annealing and D-Wave computer. I saw that it has about 5000 qubits which can solve a QUBO problem with 5000 variables.
From my understanding, if we use a gate model device, say, an ...
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Can any binary problem be solved by a QUBO?
As far as I know, if a computing problem can be solved by the quantum annealing approach, it also means the solution space should be binary, e.g., a vector that only contains either 0 and 1. Otherwise,...
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Correct implementation of Qiskit QAOA
I've been dealing with a QAOA implementation of a QUBO problem. In order to do this, I converted my QUBO matrix to a QuadraticModel. Once done, I have used ...
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Inequality constraints on D-Wave (using PyQUBO)
Inequalities cannot be directly converted into a QUBO form. By inequality, I mean something like this:
0⩽ Expression ⩽ N.
We can introduce a slack variable and convert it to an equality problem:
⟹ ...
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How to calculate the $r^{\text{th}}$ digit of $\sum ^{j−1}_{p=i}d^p_{\pm k}$ using PyQUBO?
I am going to implement "turn circuit encoding" method of
Coarse-grained lattice protein folding on a quantum annealer(Babej, Ing & Fingerhuth; 2018) using PyQUBO to run on the DWave qbsolv ...
