Questions tagged [d-wave]
A quantum computing company, based in Burnaby, British Columbia, Canada, mostly known for their quantum annealing computers. An early rendition of these, D-Wave One, was the first commercially available quantum computer. (Wikipedia)
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Comparing BQM and CQM solving for a tree-path problem
I'm currently working on a project for my thesis regarding BQM and CQM optimisation for a path problem.
Without going too much on the details, here's some info:
the structure is a tree, where all the ...
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Can D-Wave presently solve real-world problems that conventional computers cannot solve?
There are number of threads on this site about the ability of QCs solving real-world problems (see for example What are the practical applications of quantum computing in engineering by the year 2030?,...
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QPU vs. Solvers
I am trying to understand the roles of the QPU and the solvers in a quantum device, specifically I am reading for this purpose the documentation of D-Wave.
While it is clear to me that the QPU of a ...
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Does the D-Wave hardware show any advantage for academic use-cases, for example in condensed matter physics?
The D-Wave team put out a few papers (like this one and this one) in the last few years describing how their methods can find ground states of certain spin-glass Hamiltonians faster than classical ...
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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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Python code for D-Wave Annealer
In the below screenshot, I am aware of resolving the issue by reducing num_reads as the annealing time is exceeding my allowance. Although it works, my question ...
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Is there any another method for adjusting transverse field? (D'wave)
By using QUBO formula, I can't take in Transverse field equation
I was tried using of annealing schedule but it was failed .
Is there any another method for adjusting transverse field?
(I want to get ...
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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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How to keep the initial Hamiltonian in D Wave
So the D wave machine claims to start in an eigenstate of the Pauli X term in the transverse Ising model Hamiltonian,
$$
-\frac{A(s)}{2}\sum_{i} \sigma^{x}_{i}
$$
and then $A(s)$ is turned off slowly ...
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Is there any quantum annealer simulator offered by DWave?
I am searching for quantum annealer simulator offered by DWave. I found classical solvers in dimod packages that implement simulated annealing, but I couldn’t find solver that simulates the real ...
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D-Wave Cloud Service - Pricing for Academic Research Project
In D-wave's web portal, I found 3 different ways that one can gain access to more QPU/Hybrid Solver time. One of them is the academic research project. Does anyone here have experience of carrying out ...
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How to compare Quantum Annealing and Adiabatic Quantum Computing?
I'm still unsure on the difference between adiabatic quantum computing (AQC) and quantum annealing (QA). Please critique these interpretations:
AQC: Define a Hamiltonian with an easy-to-prepare ...
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Absolute value of a BQM: how to substitute it with constraint?
I need to build an expression for the objective to be minimized which is based on the L1-norm. For doing this, I need to take the absolute value of a BQM, which is not possible, at least at the moment ...
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How to add constraints to a BQM?
BQM is unconstrained by definition.
I need to submit a knapsack problem with two constraints (equality constraints + inequality constraints) to a quantum annealer (DWaveSampler).
How would you set the ...
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Why does method to_bqm not maintain variables order?
When converting to bqm with .compile().to_bqm(), the original order of the variables is not maintained.
To reproduce:
...
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What arguments point towards D-Wave devices being potentially useful?
I'm looking for any evidence pointing towards D-Wave's approach to quantum computation being promising to achieve any sort of computational advantage with respect to classical devices.
Note that I'm ...
glS♦
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How to declare non-binary decision variables in an optimization problem?
I am working on a logistics problem which require me to find the optimum quantity of product to be manufactured and also to be shipped to satisfy the customer demand. I have made a decision variable $...
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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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Can D-Wave machines be applied to simulate Hamiltonians arising in quantum physics?
AFAIK D-Wave primarily advertises their machines as tools for solving problems with classical input, i.e. when the Hamiltonian to be minimized is a function of $Z$s.
Can one use their machines in ...
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Why is quantum annealing often associated with the Ising model?
Quantum annealing is often associated with Ising Model, in the sense that the problem Hamiltonian needs to be in the form of an Ising Hamiltonian.
Is this because the physical description of the ...
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Is there any rigorous proof that Quantum Annealing provides a quantum advantage?
Is there any rigorous proof that Quantum Annealing (QA) is of any benefit (e.g. in terms of time to optimal solution, convergence rate, etc.) for a specific problem? Or any empirical evidence for the ...
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How are IBM's 127 qubits more potent than the 5760 qubits D-Wave - Advantage_system6.1?
Hi I'm a newbie in quantum computing recently I had a look at the AWS braket and I've seen they had a machine called D-Wave - Advantage_system6.1 that has 5760 qubits but when I googled the highest ...
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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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Why do Quantum Annealer have (currently) a higher scaling potential?
One may categorize quantum computers in two classes: Quantum Annealer and (universal) Gate Quantum Computers. There may be also other categories. IBM announced 127 Qubits for their next Gate Quantum ...
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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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Qubit fidelity of DWAVE device
Since DWAVE quantum device is constructed using superconducting flux qubits, each qubit cannot be produced identically so that the fidelity of the qubit must be different. DWAVE only provides the ...
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Is D-Wave advantage a noisier hardware compared to the older D-Wave 2000?
Is D-Wave Advantage noisier hardware compared to the older D-Wave 2000? There is any measure of the noise within the vendor's whitepapers, the quantum annealer analogue of e.g. decoherence time, ...
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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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How do we calculate the offset in a QUBO formulation?
I am aware that for a quadratic optimization problem, we are required to minimize $y$ where $y = x^t Q x$ where $x$ is a column vector of binary variables and $Q$ is a QUBO matrix. I have the ...
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What is the role of Josephson junctions and biases in the D-Wave qubit structure?
On the D-Wave 2000Q there are up to 2048 qubits and 5600 coupler. A commonly used picture of one of such qubits is attached below.
Each qubit is realized by a loop of niobium controlled by Josephson ...
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What should be the lowest energy of this graph isomorphism QUBO?
I am trying to study QUBO formulations of the graph isomorphism problem. I tried implementing the QUBO matrices given by the algorithms described in here. For the two input graphs therein, I am ...
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Sampling from a given Boltzmann distribution using D-Wave systems
For a project I'm working on, I want to use D-Wave systems to estimate the probabilities of a Boltzmann distribution given a QUBO (Hamiltonian), this being performed through sampling and the use of ...
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From general 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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How is eigendecomposition of a Hamiltonian equivalent to finding the minimum of an energy function?
This question is in regards to Dwave's quantum computer which is tailored to solve QUBO problems using quantum annealing.
QM tells us that the ground state of a quantum system is given by the ...
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The Adiabatic Theorem - How to derive Schrödinger equation in the "s" variable
I'm studying Adiabatic Quantum computing from the book
"Adiabatic Quantum Computation and Quantum Annealing: Theory and Practice" by Catherine C. McGeoch at D-Wave.
The section THE ...
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Output of D-Wave LeapHybrid solver takes long to evaluate
we made the strange observation that the evaluation of the output in form of the dimod.SampleSet takes a long time to evaluate especially in comparison to the actual sampling step. Here is a minimal ...
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How to improve embedding process in D-Wave?
I am quite new to the quantum computing field.
Currently, I am trying to solve a combinatorial optimization problem on a D-Wave system, which I successfully translated into QUBO form. I also managed ...
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What do the numbers in the Ising sampleset mean?
I am trying to create a portfolio optimization with the DWave Quantum Computer. I wrote some code trying to somehow reconstruct the following Ising model paper:
Ai ...
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What is the state-of-the-art annealing device for solving Ising problems?
I understand that in addition to D-Wave's quantum annealer, there have been other unconventional (although non-quantum) Ising solvers like the one from Toshiba, Fujitsu, the Coherent Ising machine, ...
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How to decide bias in Hamiltonian Ising model?
I am trying to code finance portfolio optimisation problem into a quantum annealer, using the Hamiltonian Ising model. I am using the dwave module
...
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Why is it so important to have uniform chain lengths in a minor embedding?
Very brief background
In quantum annealing, the discrete optimization problem we wish to solve (such as finding the minimum of $b_1b_2 - 3b_1 + 5b_3b_4$ for binary variables $b_i$) may have a ...
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From Qiskit QuadraticProgram to problem model accepted by d'wave ocean
Is there a way to convert QuadraticProgram (qiskit.optimization.problems.QuadraticProgram) to BQM used in D'wave ocean (e.g. <...
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What is the computational complexity of quantum annealing?
Quantum annealing can be thought of as a black box solver that can find approximate solutions to hard optimization problems. For example, D-Wave quantum annealers can approximately solve quadratic ...
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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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D-WAVE QUBO Matrix Form
I am trying to write down this problem (friend/enemy graph) in a polynomial matrix form in order to understand quantum annealing better, but it seems like the problem should actually be split into ...
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What is the query complexity of the QUBO algorithm?
What is the complexity of the quantum unconstrained binary optimization (QUBO) algorithm in the number of queries to the quantum processor?
To clarify, I'm asking about the complexity on quantum ...
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The commutation relation $[H_d, \sum_{i = 1}^n \sigma_i^z] = 0$ from the paper about the constrained quantum annealing (CQA)
A quote from the paper "Quantum annealing for constrained optimization" by I. Hen, F. M. Spedalieri:
Let us now consider the driver Hamiltonian
$$H_d = - \sum_{i=1}^n \left( \sigma_i^x \...
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Moore's law for quantum computers
Moore's law states that performance of classical computers doubles every two years (later revised to 18 months) and a price for computing resources halves during same time period.
Currently, it seems ...
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How do IBM, D-Wave, etc. change phase physically?
How do IBM, D-Wave, etc. change phase physically? In real hardware?
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