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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Qiskit bad unitary decomposition

I want to decompose a two-qubit unitary gate $U$, $$U = e^{-i \cdot \frac{t}{2} \cdot Z_1 \cdot Z_2}\,,$$ where $t$ is an angle. I already know the right decomposition but Qiskit gives me an ...
Daniele Trisciani's user avatar
1 vote
1 answer
49 views

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
-2 votes
0 answers
60 views

How to solve an optimization problem that includes "continuous" variables with constrains using QAOA/VQE?

Here is the code from the previous question I asked on the same topic: How to solve quadratic programming problems with continuous variables and continuous constraints by using quantum algorithms? ...
said zhn's user avatar
1 vote
1 answer
102 views

How to solve quadratic programming problems with continuous variables and continous constraints by using quantum algorithms?

enter image description here Here is my optimization problem I solve with classical optimization using DocPlex but I want to solve using quadratic program using Qiskit and QAOA as solver ...
said zhn's user avatar
3 votes
0 answers
67 views

Why don't we start evolution with ground state in QAOAnsatz?

The adiabatic theorem states that we can start from an eigenstate, slowly change our Hamiltonian and still remain in the eigenstate. In the vanilla QAOA we start from $|+\rangle^n$, which is the ...
HaraldRudobrody's user avatar
1 vote
0 answers
65 views

Error code 1217, Message: Reduce time between submitting subsequent jobs in a session

I tried running a piece of Qiskit code to minimize a Hamiltonian using QAOA. I tried running the same piece of code that I had used earlier in the IBM Quantum system 'ibm_nairobi' which gave me the ...
Jane's user avatar
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1 vote
1 answer
66 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
3 votes
0 answers
40 views

qiskit QAOA on Aer GPU giving errors

I am trying to run Qiskit QAOA algorithm on using aer simulator and device GPU. But I am not sure how to give this backend in the QAOA algorithm structure. Here is ...
to_batman's user avatar
3 votes
0 answers
44 views

How to update angles

I am struggling to understand the concept of updating angles in a parameterized algorithm. Assume I have an objective function $x^2+1$ that I want to optimize using QAOA which can handle continuous ...
34341's user avatar
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4 votes
1 answer
74 views

Retrieving job result attributes in Qiskit

I am trying to optimize a Hamiltonian using QAOA in IBM Qiskit. I used the following 'minimize' function to get my result. (I am not including the whole code because it will get unnecessarily long). <...
Jane's user avatar
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3 votes
0 answers
32 views

How can one use QAOA to obtain parameters that approximate the first excited state of the target Hamiltonian?

One can use QAOA to find the ground state and its energy by minimizing the expectation value of a target Hamiltonian (say, $H_T$) with respect to the QAOA ansatz and obtaining optimal parameters ...
Pratham Hullamballi's user avatar
2 votes
1 answer
71 views

Qiskit qubit ordering

In their to_ising documantation page, Qiskit devs mark the comment: Variables are mapped to qubits in the same order, i.e., $i$-th variable is mapped to $i$-th ...
Alternative7's user avatar
1 vote
0 answers
103 views

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
72 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
51 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
4 votes
0 answers
135 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
38 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
91 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
49 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 vote
1 answer
55 views

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
0 votes
0 answers
31 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
5 votes
0 answers
115 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
103 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
44 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
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0 votes
2 answers
159 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
85 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
86 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
64 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
345 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
4 votes
1 answer
155 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
0 votes
0 answers
112 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
42 views

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
128 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
  • 105
4 votes
1 answer
215 views

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
  • 177
0 votes
1 answer
73 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
53 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
86 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
109 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
175 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
69 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
232 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
203 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
669 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
357 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
109 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
153 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
39 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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4 votes
0 answers
72 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
4 votes
1 answer
288 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
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