Questions tagged [qubo]

Questions about or related to QUBO (quadratic unconstrained binary-function optimization).

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How to convert QUBO (with non-zero diagonal elements) to Maxcut?

I want to solve QUBO with non-zero diagonal elements in matrix Q using QAOA. But I want to solve for a large enough problem size (30+ variables) and hence want to divide my circuit into subcircuits. ...
Oleksii's user avatar
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How to add expressions to a Binary Quadratic Model, similar to CQM?

In a constrained quadratic model, we are able to create expressions like this: ...
underdog987's user avatar
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1 answer
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Question on efficiency of HOBO Quadratization and other depth reducing techniques

I am having trouble understanding some concepts in Quadratizing a high order polynomial. I am reading the review "Quadratization in Discrete Optimization and Quantum Mechanics" . I would ...
QuantumTheoretical's user avatar
1 vote
1 answer
108 views

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(...
Shadow43375's user avatar
2 votes
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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 ...
underdog987's user avatar
19 votes
2 answers
2k views

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 ...
sheesymcdeezy's user avatar
1 vote
0 answers
104 views

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, ...
Сударь Сударев's user avatar
1 vote
1 answer
86 views

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 ...
Amedeo Bertuzzi's user avatar
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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: ...
SimoneGasperini's user avatar
-1 votes
1 answer
136 views

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 ...
James's user avatar
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5 votes
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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 ...
underdog987's user avatar
1 vote
1 answer
377 views

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 ...
Rogue8989's user avatar
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226 views

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^{\...
Waqas Parvaiz's user avatar
2 votes
2 answers
192 views

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 ...
Van Peer's user avatar
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1 answer
180 views

qiskit: convert from ising result to qubo result?

I have a very simple qubo problem: ...
voxter's user avatar
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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 ...
T. Zaborniak's user avatar
1 vote
1 answer
329 views

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 & ...
MYang's user avatar
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2 votes
0 answers
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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 ...
Hirschi's user avatar
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3 votes
1 answer
333 views

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 ...
Kai-Chun Lin's user avatar
0 votes
0 answers
148 views

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. ...
Kai-Chun Lin's user avatar
2 votes
0 answers
173 views

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 ...
Ket's user avatar
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6 votes
1 answer
235 views

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 ...
peachnuts's user avatar
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3 votes
1 answer
130 views

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,...
Kai-Chun Lin's user avatar
0 votes
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211 views

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 ...
evil_potato's user avatar
9 votes
1 answer
578 views

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: ⟹ ...
amp's user avatar
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5 votes
0 answers
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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 ...
Hasitha Perera's user avatar