Questions tagged [qaoa]

For questions about the Quantum Approximate Optimization Algorithm (QAOA), first introduced in Farhi, Goldstone, Gutmann 2014 (https://arxiv.org/abs/1411.4028).

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Converting Ising Hamiltonian to a Circuit in Qiskit

I tried to solve a 2-node TSP (travelling salesman problem) by implementing QAOA on Qiskit. The graph looks like: Then I used the related Qiskit functions to convert the graph to the QUBO and map it ...
Alternative7's user avatar
1 vote
0 answers
32 views

Building a problem unitary circuit for QAOA on Qiskit

I am trying to build a circuit for QAOA that solves a Traveling Salesman's Problem, which can be represented as a complete graph with 4 nodes. After formulating the problem as a QUBO and mapping it ...
Alternative7's user avatar
1 vote
1 answer
40 views

How are edge weights "loaded" in the problem hamiltonian when solving TSP with QAOA?

I've come across several of the QAOA tutorials, and yet I'm afraid I haven't found any explanation on this. According to the Qiskit tutorial on QAOA, the cost function for the target problem has a ...
Alternative7's user avatar
3 votes
0 answers
57 views

Qiskit QAOA optimization does not work when setting simulation seed in AerSampler

I am using Qiskit's QAOA for optimization and I would like to extract the probabilities distribution obtained in the optimization loop when running the circuit with the optimal parameters set. To do ...
user26100's user avatar
2 votes
0 answers
23 views

Implementing Adiabatic Grover Search via QAOA

I am reading the paper Grover Search Inspired Alternating Operator Ansatz of Quantum Approximate Optimization Algorithm for Search Problems. The paper proposes running the Adiabatic Grover Search ...
user82261's user avatar
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IS my QUBO too big for QAOA using IBM Quantum computer?

On qiskit, I have defined a QUBO, called qp as follows: ...
Stéphane's user avatar
1 vote
1 answer
65 views

QAOA on weighted graphs

I tried to use the QAOA to solve the MaxCut problem on a 10 nodes weighted graph and run the simulation on qiskit from $p = 1$ to $p = 6$. I was expecting to get closer to the real solution as $p$ ...
Mattia Chiurco's user avatar
1 vote
0 answers
35 views

Link between AQC and QAOA

I try to understand precisely the link between AQC and QAOA, through the Trotter-Suzuki formula. A similar question is Derivation of QAOA from AQC, but I was asked by moderators to post my question ...
deb2014's user avatar
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1 answer
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How to add a circuit layer after computing QAOA layer

I have used the Qiskit-based QAOA function to solve a combinatorial problem tsp, and I want to append a circuit after the QAOA layer, is there any way to do that? Qaoa
Affan Hussain's user avatar
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0 answers
24 views

How to tune QAOAAnsatz when solution is known to have a certain form?

I'm running QAOAAnsatz in QisKit, and I know that the solution to my problem has a certain form. Namely: ...
IsalanOnkar's user avatar
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0 answers
54 views

How to change the simulator used by Qiskit's `QAOA` (or get around the "Maximum allowed dimension exceeded" error)?

I'm running MinimumEigenOptimizer with QAOA on a large quadratic program: ...
somewhere's user avatar
5 votes
0 answers
71 views

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
5 votes
1 answer
75 views

Recent experimental demonstrations of variational quantum algorithms?

I am interested in the recent experimental demonstrations of variational quantum algorithms. Can someone please provide me with a list of references of recent experimental demonstrations of ...
Soumik Adhikary's user avatar
1 vote
0 answers
28 views

'Continuous' (Classical) Cost function for QAOA

I have some combinatorial optimization problems which I would like to analyze using QAOA. These problems are coming from various applications in scientific computing such as solving PDEs. Some of ...
user82261's user avatar
  • 181
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2 answers
91 views

How to get angles optimized by classical optimizer from QisKit's QAOA Module?

I have the following simple optimization in QAOA: ...
somewhere's user avatar
1 vote
0 answers
65 views

QAOA algorithm from qiskit.algorithms.minimum_eigensolvers sends jobs without stopping

I don't know why the code keeps sending jobs. The code is: ...
Mattia Chiurco's user avatar
0 votes
1 answer
49 views

Portfolio optimization via quantum Zeno dynamics in Qiskit

Recently, I came across paper Portfolio Optimization via Quantum Zeno Dynamics on a Quantum Processor. In the paper, a new approach to optimization with QAOA is introduced. Instead of employing a ...
Martin Vesely's user avatar
3 votes
1 answer
52 views

How to sanity check QAOA cost Hamiltonian?

I'm trying to learn QAOA and how to apply it to a complex combinatorial problem. But for the purpose of this question I'll use the common example MaxCut. I'd like to know if I've set up my cost ...
somewhere's user avatar
3 votes
2 answers
149 views

Does QAOA require that the problem Hamiltonian be an Ising Hamiltonian as a quadratic function of the spin variables?

In the context of QAOA, I often see the problem Hamiltonian being called an "Ising Hamiltonian", and shortly after, I that the Hamiltonian is a quadratic function of the spin variables. Is ...
underdog987's user avatar
3 votes
1 answer
118 views

Does QAO Ansatz have any better performance guarantees than QAOA?

QAOA is a well-known heuristic for solving optimization problems, and it has the desirable property that as p -> infinity, the true minimum objective function value is reached. There is a ...
IsalanOnkar's user avatar
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0 answers
92 views

Combinatorial optimization problems solving using VQE

I'm studying about the variational quantum algorithms and I would like to know about the usage of VQE for solving combinatorial optimization problems. VQE can find the ground state energy of a given ...
William's user avatar
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2 votes
0 answers
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Can we easily find the ground states for one-dimensional ANNNI-like Ising models?

The Hamiltonian for a simple one-dimensional Ising model on a finite (linear) chain of $L$ spin-half particles might be: $$H = -J \sum_{i=0}^{L-1} \sigma_i^z \sigma_{i+1}^z.\tag{1}$$ The interactions ...
Mark Spinelli's user avatar
4 votes
0 answers
117 views

Probability inequality for Quantum Approximate Optimization Algorithm (QAOA)

In arXiv:2207.14734 the authors claim that it is "straightforward to show that" their equation 8 holds: $$\mathrm{Pr}_{x\sim q}[x:f(x)\geq \mu] \geq \frac{1}{M}$$ where we have an objective ...
Juri V's user avatar
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0 answers
34 views

Variational Quantum Algorithms for Graph Traversal

I have a combinatorial optimization problem which on a first pass I think boils down to finding a path with a maximal score. The score for a path is computed by an auxiliary function. Are there near-...
user82261's user avatar
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4 votes
1 answer
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Derivation of QAOA from AQC

In adiabatic quantum optimization we start with an initial Hamiltonian $H_0$ and then adiabatically evolve from $H_0$ to $H_P$ (problem hamiltonian) for a time $T$ according to \begin{equation}\label{...
nuemlouno's user avatar
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Maximize the Sum of absolut Vector elements with QAOA

Im trying to get started with QAOA. I tried to program a simple example for testing my understanding. The goal is to maximize $z^TV$ with $V \in \mathbb{R}^{nx1},z \in ${$-1,1$}$^n$. I tried ...
H_Infinity's user avatar
0 votes
1 answer
55 views

Using BFGS for MAXCUT

In the original Qiskit QAOA implementation, the sample uses COBYLA as the classical optimizer in the following code segment: ...
Evan Camilleri's user avatar
1 vote
0 answers
36 views

Qiskit: The parameters of the circuits constructed by QAOAAnsatz will change after decomposition and transpilation

When I submit a parametrized circuit as an input for the mixed operator in QAOAAnsatz, some strange results appear. For example, when I submit a parametrized ...
user23270's user avatar
2 votes
0 answers
59 views

Custom Mixer for QAOA for Graph Coloring, where to start?

I am trying to implement QAOA for graph coloring with hard constraints. In this paper, eq. 9 a custom mixer is proposed, is looks like this: $B_{ui} = \frac{1}{2^{l + 1}}(X_{u0}X_{u1} + Y_{u0}Y_{u1}) \...
Himera Ephemera's user avatar
1 vote
0 answers
60 views

Applying horizontal dots in a LaTeX Quantum Circuit diagram [closed]

I am almost done with my circuit diagram for the QAOA circuit but the \cdots does not want to cooperate. As seen there exists some wire drawn across the dots from the gate to the right and I can't ...
Erik Bashore's user avatar
0 votes
1 answer
124 views

Finding the minimum cut using QAOA

I am trying to find the minimum cut for a given graph. I am using QAOA and refering to the qiskit textbook: https://qiskit.org/textbook/ch-applications/qaoa.html. I understand I need to find the ...
epsilonolispe's user avatar
2 votes
1 answer
59 views

What happened to the 1/2 in the MAXCUT Problem Unitary for QAOA

I recently started to begin with QuantumComputing following the Qiskit tutorial. I worked through the basics and now reached Chapter 4.1.3 (https://qiskit.org/textbook/ch-applications/qaoa.html). I ...
H_Infinity's user avatar
1 vote
1 answer
175 views

Commutativity of XY gate

My question is a simple one: Can 2 XY gates commute ? XY gate is a 2-qubit XX+YY interaction also sometimes referred to as iSwap gate.
Marouane Jaakik's user avatar
0 votes
1 answer
143 views

Implementation of QAOA to solve version of knapsack problem

Say I want to fill a knapsack with as many things as possible. I don't care about what they are, simply the number. But I don't want the total weight to exceed a set limit. [https://qiskit.org/...
MeltedStatementRecognizing's user avatar
1 vote
1 answer
441 views

QAOA MaxCut IBM Qiskit Example

I tried using the same example of Qiskit MAX-CUT problem for a different graph. https://qiskit.org/textbook/ch-applications/qaoa.html My graph is as follows: Using COBYLA I get a cut which is NOT a ...
Evan Camilleri's user avatar
1 vote
1 answer
257 views

Implementing QAOA Hamiltonian for MAX-3-SAT in Qiskit

I have read about how QAOA is used to tackle the MAX-CUT problem and wanted to test my understanding by trying to implement some code to approximate the MAX-3-SAT problem. To do so, I considered the ...
Giorgos Giapitzakis's user avatar
1 vote
1 answer
85 views

Calculating state fidelity and space complexity of Minimum Eigen Optimizers (VQE, QAOA and Grover Optimizer) in qiskit

I'm a beginner in using Qiskit and my Computer Science background is not extensive. But I understand the Quantum Physics aspects of it relatively well. I solved a QUBO problem in Qiskit using VQE (...
Janani Ananthanarayanan's user avatar
1 vote
0 answers
118 views

Interpreting VQE and QAOA based solutions in portfolio optimization

I am going through portfolio optimization using Qiskit. It really looks interesting. The module has both VQE and QAOA algorithms for optimizing the portfolios. In the VQE based solution the ...
Rag's user avatar
  • 31
1 vote
0 answers
29 views

Error analysis on the approximation of an adiabatic evolution operator by a QAOA circuit

I would like to know what would be the approximation error of a QAOA circuit. Suppose we have time-dependent Hamiltonian $H(t) = (1 - s(t))H_{init} + s(t)H_{prob}$ where $H_{init}$ in an initial ...
MonteNero's user avatar
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3 votes
0 answers
66 views

Does the Lie closure of a set of Hamiltonians describe all unitaries you can generate with them?

Suppose we have $k$ Hermitian matrices $H_1, ..., H_k \in M_d(\mathbb{C})$. Define $\mathfrak{g} = \langle iH_1, ... iH_k \rangle_{\text{Lie}}$ to be the Lie algebra generated by these Hermitian ...
Alexey Uvarov's user avatar
3 votes
1 answer
241 views

Qiskit unable to transpile the circuit for Rigetti Aspen M 1 on AWS

I am trying to run a Qiskit QAOA algorithm on AWS Rigetti Aspen M 1 Backend using qiskit braket provider. However qiskit is not able to properly transpile the circuit ...
3.14159's user avatar
  • 31
2 votes
1 answer
136 views

For the same operator, when I use qiskit's VQE and QAOA solutions, the results are completely different

Specifically, I can't get the correct result using QAOA,A total of 6 qubits were used in this work,this is part of my code using VQE and QAOA localsim = BasicAer.get_backend('qasm_simulator') ...
Zachary's user avatar
  • 21
3 votes
1 answer
422 views

Choosing a different optimizer when running QAOA in qiskit

I am trying to reproduce the QAOA example from https://qiskit.org/textbook/ch-applications/qaoa.html and learn how to opt for a different optimizer. The relevant block in the example is (towards the ...
Marion's user avatar
  • 585
3 votes
2 answers
268 views

qiskit qaoa.compute_minimum_eigenvalue

I am having some trouble running the compute_minimum_eigenvalue method from qiskit's QAOA: the documentation states that one ...
Lord Nexprex's user avatar
0 votes
1 answer
50 views

Validating existing QAOA, deprecated solutions on qiskit

I'm currently evaluating a static QC, QML and QAOA approach to solving a combinational problem. My solution with the static QC and QML approach is finished, and all data has been collected. Now, the ...
Ricardo's user avatar
  • 179
2 votes
2 answers
464 views

Qiskit compute mean expectation value

I want to calculate the mean expectation value of an PauliSumOp within qiskit after I executed a QAOA Circuit. My approach is the following: ...
DilanChecker's user avatar
3 votes
1 answer
99 views

Understanding QAOA from Basics/scratch

Recently after working on QAOA with finance and graph coloring problems. I have started exploring the QAOA from scratch. I would like to understand the QAOA derivation mathematically and have started ...
anonymousKet's user avatar
2 votes
0 answers
138 views

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
  • 21
3 votes
2 answers
414 views

Why do we decompose the hamiltonian into Pauli strings to measure the expectation value?

Measuring the expectation value of a hamiltonian is an essential step in some algorithms like QAOA. I noticed that the procedure always starts with decomposing the hamiltonian into a sum of Pauli ...
bubakazouba's user avatar
4 votes
0 answers
134 views

Why does QAOA's performance monotonically increase as p increases?

From A Quantum Approximate Optimization Algorithm - Farhi et al. The Quantum Approximate Optimization Algorithm has the key feature that as p increases the approximation improves. We contrast this to ...
bubakazouba's user avatar