Unanswered Questions
310 questions with no upvoted or accepted answers
3
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How to construct the oracle for Grover's search to solve the traveling salesman problem?
Consider the modified version of the Traveling Salesman Problem where you are searching for a path of length less than some $k$. We can solve this problem using Grover's search where we encode each ...
glS♦
- 26.9k
3
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174
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How to define initial state $\rvert \Psi(0) \rangle \equiv \rvert 1, -1 \rangle \otimes \rvert 0 \rangle_{\text{cav}} $ of a system in QuTiP?
Say, we have a $\require{mhchem}\ce{^87Rb}$ atom having an electric dipole transition on the $D_{1}$ line and we have two hyperfine ground states, one on $F = 1$ and one on $F = 2$ level. So, we take ...
- 31
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Synchronous Interactions Between Quantum and Macroscopic Systems
Synchronous Interactions Between Quantum and Macroscopic Systems
Lester Ingber
This project calculates synchronous quantum systems and macroscopic systems with well-defined interactions. I would ...
3
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0
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93
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How to add states on the Bloch sphere from a master equation?
Can you please help me to find an answer to this question: I am using qutip for the study of quantum systems. suppose I have calculated the solution of the master equation using the ...
- 71
3
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142
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Measurement inconsistency in Qiskit
I am using Qiskit in an algorithm. In the end, I am measuring exactly a register of 4 qubits but the histograms show states with 5 qubits.
This is the code I used:
...
- 17.8k
3
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131
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What are reasonable noise/dephasing parameters for QuEST to emulate state-of-the-art quantum computers?
The QuEST code allows for simulation of quantum computers taking dephasing and depolarizing noise into account via one and two qubit dephasing and depolarization. What are realistic parameters for ...
- 17.8k
3
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672
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Qiskit Python program cannot connect to QE API
I am just getting started with Qiskit and IBM Quantum Experience, so please forgive my newby question.
I have a IBM Quantum Experience account and I generated an API token.
I used the generated ...
- 17.8k
2
votes
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answers
77
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How to simulate a beam splitter in QuTiP?
I'm trying to mix two states on a beam splitter whose unitary operator is
$$\hat{U}=e^{i\theta \left( \hat{a}^†\hat{b} + \hat{a}\hat{b}^† \right)},$$
where $\hat{a}$, $\hat{b}$ are annihilation ...
- 21
2
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answers
88
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Is there a theoretical method to achieve a positive semi-definite density matrix in QST?
The problem of encountering negative eigenvalues in the density matrix during Quantum State Tomography (QST) is well-explained in this Quantum Computing Stack Exchange post.
However, I am seeking ...
- 7,969
2
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66
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Error code 1217: "Session has been closed"
I am currently studying algorithms related to VQA. I have built a circuit to calculate the cost function and optimized it using a classical optimizer. During the initial optimization iterations, ...
- 53
2
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Are qiskit and qiskit aer identical or very similar in syntax?
I can't afford a IBM full access account, and can't learn an entire programming language with only ten minutes of run time a month.
Are the qiskit lessons on YouTube/ github transferable given that I ...
- 61
2
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145
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Layout error with after compilation with custom Qiskit pass manager
I am trying to implement the custom Qiskit pass manager from this paper. The code from the authors is provided here on GitHub. I am able to get the pass manager working, and a compiled circuit is ...
- 2,593
2
votes
1
answer
84
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Transpile and run don't use GPU device
I'm trying to run an implementation of Shor's algorithm using a GPU device. While running with $N<1023$ works (23 qubits), when running with a higher number of qubits, the program ends before ...
CommunityBot
- 1
2
votes
0
answers
53
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Value error in variational quantum circuits
I am working on a project to find a unitary gate that arrives at a specific density matrix at the end. The circuit construct is shown below:
...
glS♦
- 26.9k
2
votes
0
answers
43
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Quantum Convolutional Neural Network not producing gradients
I am trying to bulid a quantum convolutional neural network for image classification with Pennylane and Keras but the model isn't training and I keep getting the warning:
WARNING:tensorflow:Gradients ...
- 21