# Questions tagged [pennylane]

PennyLane is a cross-platform Python library for quantum machine learning, automatic differentiation, and optimization of hybrid quantum-classical computations.

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### What are the benefits of using quantum machine learning?

I have been investigating uses for quantum machine learning, and have made a few working examples (variations of variational quantum classifiers using PennyLane). However, my issue now is its ...
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### What are the differences between the IBM machines?

I'm quite new to this field, and have started sending jobs to IBM's quantum computers. I have access to around 11 locations. I can see that these have different numbers of qubits within them, and then ...
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### Pennylane and Qiskit for quantum machine learning

I'm interested in quantum computing, specifically in “quantum machine learning” (QML). I'm going to start my masters program in computer science and have previous experience in classical machine ...
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### How linear combination of unitaries gradient work (Qiskit, PennyLane)?

I'm trying to implement linear combination of unitaries(LCU) gradient from Qiskit Gradient Framework but on PennyLane. First, i looked through the source code in Qiskit. In Qiskit LCU gradient if we ...
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### Pennylane: creating QNodes for large numbers of circuits that only differ by number of wires

Take the following simple quantum function: ...
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### Computing expectation value of product of observables in PennyLane

In PennyLane, the following circuit returns the expectation value of the PauliZ observable on qubit (wire) 1: ...
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### How to create the equivalent of the Qiskit rxx gate in Pennylane?

How can I create the Pennylane equivalent of: from qiskit import QuantumCircuit circ = QuantumCircuit(2, 2) circ.rxx(theta=0.3, qubit1=0, qubit2=1)
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### How can I write unit tests for a pennylane circuit?

I have several mixing unitary circuits written using Pennylane to be used in the QAOA algorithm. Furthermore, I'd like to write unit tests for these mixing circuits to ensure that the code is doing ...
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### Differentiable Programming of Quantum Computers

Recently, I have tried PennyLane and TensorFlow Quantum. These platforms are said to provide differentiable programming of quantum computers but I can't understand it clearly though. I have searched ...
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### Implementation of Unitary in Shor's Algorithm in PennyLane

I've been working on implementing Shor's Algorithm in PennyLane, but am struggling to understand how the circuit for 'U' has been constructed according to Qiskit. In the Qiskit textbook, they seek to ...
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### What is the most efficient method to update the binary encoded values inside a quantum state?

We're implementing a QML algorithm in which we have to update the value stored inside a quantum state which is strictly unknown to us, by multiplying it with a real number classically stored with us. ...
284 views

### PennyLane operations - Kerr, Displacement and Squeeze

I am familiar with the quantum gates of Qiskit, but I become very confused when looking at the continuous variable (CV) operations in the PennyLane documentation. I am especially interested in the ...
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### Expected value of a product of the Pauli matrices in different bases

I'm trying to reproduce the results of this article https://arxiv.org/abs/1801.03897, using Qiskit and Xanadu PennyLane. Particularly, this part with expected values of the Pauli operators: For ...
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### VQE from scratch, what have I got wrong?

I've been working on a code to run VQE with a grouped measurement. For some reason, my expectation values are slightly off from those computed by pennylane, the software I decided to use for this ...
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### How to convert Pennylane decompose_hamiltonian to Cirq PauliString?

I have a matrix that I would like to decompose into a Pauli String. Pennylane's qml.utils.decompose_hamiltonian does this and returns a list of coefficients and a list of operations representing the ...
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### Quantum Phase Estimation - Should be getting exact answer

Having read the Qiskit demonstration in the Qiskit textbook on how to implement Quantum Phase Estimation, I tried to do so on PennyLane's framework. My code pretty well follows what was done in Qiskit,...
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441 views

### QUBO defined in Qiskit/DOcplex: how to solve it using Pennylane?

I have a complex Integer Linear Programming model defined in DOcplex/Qiskit representing a combinatorial optimization problem. Using the Qiskit utils, it is possible to covert it to either an Ising ...
142 views

### pennylane: How to carry out MB rotation without CB rotation?

I'm looking at this MBQC tutorial where there's an example that shows that a MB and CB single qubit rotations give the same result. CB version : ...
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### Problems trying to plot the classical Fisher information with Pennylane

I'm working with pennylane. My goal is to plot CFI(Classical Fisher Information)with following quantum state. With the above equation I set gamma as 0. Then It becomes: If gamma is not equal to zero,...
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### Is pennylane free?

I was going through the basics of pennylane. I am able to understand that it is used for quantum neural networks. I am not sure whether it is using paid cloud computer or simulator of xandu or ibmq? ...
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### SLSQP optimizer(scipy.minimize) doesn't update parameters

I'm trying to find optimal parameters that minimize the cost functions. In cost function, it calculates the classical-fisher-information at a certain point(phi[0] = np.pi). Cost-function takes 3-...
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### Post-selection on pennylane

I want to do something like this: For a single-qubit Apply Hadamard -> Time_evolution -> Phase_damping -> Hadamard -> Post-selection -> Get CFI(classical fisher info) Density matrix ...
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### Computing gradients in parallel with cost from probs (Pennylane-Braket)

Do circuits that measure probabilities instead of expectation values benefit from parallel execution? The Computing gradients in parallel with Amazon Braket tutorial shows how the multiple device ...
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1 vote