All Questions
Tagged with python or programming
1,724 questions
2
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How to use Qiskit translation pass manager with Clifford + T gate basis?
Context
In qiskit, the translation stage of the transpilation "translates (or unrolls) the gates specified in a circuit to the native basis gates of a specified backend." (cf doc)
For that, ...
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1
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0
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43
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Operation 'sx' is not defined for this system
Any one knows how to resolve the below error:Operation 'sx' is not defined for this system. The below code works really well with ...
- 219
1
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0
answers
14
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Periodic electric field link operator in QuSpin
I am trying to implement a truncated bosonic Hilbert space as described in Eqs. (15) and (16) of this paper on simulating the Schwinger model. However, I am unable to implement the "periodic ...
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1
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0
answers
21
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What is the difference between `HighLevelSynthesis` and `UnrollCustomDefinitions` qiskit transpilation passes?
The doc for UnrollCustomDefinitions indicates :
...
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1
vote
1
answer
255
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Simple successor gate
I want to create a gate that, given a sequence of qbits that encode n, transforms that sequence in n+1, in other words the successor function. I managed to do it in qiskit by writing this:
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- 113
1
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0
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33
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I have trouble using the alternatives for some commands in older versions of qiskit
I have a code that calculates the transition amplitute between and using the ZZFeatureMap with 4 repetitions and default data mapping function. Use the qasm_simulator with shots = 8192, seed_simulator ...
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1
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0
answers
12
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Custom Feature Map Error for VQR in Qiskit 'Input data has incorrect shape, last dimension is not equal to the number of inputs'
I am trying to use a VQR for solving a regression problem. My data has 5 features, I want to use 4 features to estimate 5th one. I made it work with ZFeatureMap but now I want to create my own feature ...
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2
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1
answer
110
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why does this get DAGCircuitError?
When I run the simple circuit that just does multi-controlled rotation I had the error:
"DAGCircuitError: 'bit mapping invalid: expected 4, got 1'".
It seems the error occurs when a ...
1
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0
answers
17
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How to get historical calibration data for mthree (M3) from IBM Quantum devices?
I'm using mthree in Batch mode. A batch needs to be queued before it can be executed. The time when a batch was executed can be obtained from the IBM Quantum Platform site, so I would like to obtain ...
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-4
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1
answer
54
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What if oscillation-based computing is the generalization of quantum computing? [closed]
This question contains both engineering perspectives and science perspectives.
Here is my definition about oscillation-based computing:
Oscillation-based computing is the computation where the input ...
2
votes
1
answer
46
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Comparing Qiskit gates with numpy functions
I am trying to understand how Qiskit's gates work by comparing the outputs of a simple circuit with numpy matrix algebra.
If I start with two qubits and apply a rotation gate to each of them, I get:
<...
2
votes
1
answer
106
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Fastest method to find any single error for a given stabilizer set and given syndrome
I am working on trellis structures of stabilizer codes, where I construct a trellis for a given set of stabilizer generators and a given syndrome. I want to find any arbitrary error out of all the ...
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2
votes
1
answer
325
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Migrate Algorithm using latest IBM Qiskit SKD (v1.2.4) for Python
I am looking for an implementation of an algorithm using the IBM Qiskit SDK for Python.
I know that there is an implementation for Qiskit v0.x but I am missing an implementation for the current/latest ...
- 23
1
vote
1
answer
93
views
Actual execution time on real hardware
I am trying to calculate the actual execution time on real HW. We have access for IBMQ systems.
What I am thinking is that to find the actual execution time on real HW so that we can know whether our ...
- 219
0
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0
answers
46
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How to learn mathematics and physics for quantum computing
I am currently pursuing my bachelor's in computer science (AI). I am very passionate and curious about quantum technologies, particularly quantum information theory, and quantum computing, and I want ...
1
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0
answers
41
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Quantum register for variable store - how to encode operations?
Suppose I have a lot of classic variables of a certain number of bits in size, say, 8 bits. Instead of starting each variable from zero in superposition, I want to use the exponential space to encode ...
- 171
2
votes
1
answer
143
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The number of qubits of the ansatz does not match the operator
I am trying to run my below code on FakeSherbrooke() system, but I am getting an error as shown below:
...
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0
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0
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31
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Discarding a Quantum register to extract kernel matrix in practical quantum computer
Question: How to extract a kernel matrix from a quantum state on a real quantum computer through discarding a register?
I am trying to understand the paper "Quantum Support Vector Machine for Big ...
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1
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1
answer
76
views
Where are quantum register operations defined?
Suppose I have three registers of many qubits, $$x, y, r$$
I want to define a quantum gate mapping the sum of $x$ and $y$ to $r$, or more generally from any operation over $x$ and $y$ to $r$. The ...
- 171
1
vote
1
answer
46
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QPE implementation with 4 qubits
I'm trying to implement a circuit for QPE, i start with 4 qubits but the results are incorrect (even for 3 or 5 qubits).
the used unitary gate is : ...
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0
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0
answers
54
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Usage of custom passes during transpilation
I am reading a lot about custom passes in the qiskit like
...
- 219
0
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0
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60
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Cannot Find referance DeutschJozsa in __init__.py
I am new to quantum computing and Python. I tried to make a quantum simulation with qiskit, but I have some import issues that I can't solve, and I decided to ask it here.
I tried to import ...
0
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0
answers
36
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How to generate random quantum states in matlab?
I was wondering if there is some academic standard/any way of generating random n times n q-states/density matrices in Matlab without using any other package then QETLAB.
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-2
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1
answer
82
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No module named qiskit-algorithm
I want to try the quantum computing simulator, but when I try to import the Algorithm, the Qiskit shows an error. For your information, I am currently running Qiskit using Google Colab.
This is the ...
2
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1
answer
110
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How to download historical calibration data from IBM quantum devices?
I want to download the data tables from either the current QPUs or the previous ones (that have fewer qubits) from IBMQuantum. However, when I try to look at answers like Is there an archive of IBMQ ...
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-5
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1
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60
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0
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0
answers
45
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RuntimeJobFailureError: 'Unable to retrieve job result. Error code 1520; The instruction cost per qubit exceeds the system limit
I want to find two operands of multiplication result of 180. In another word, finding integer factors of 180.
I'm using ...
1
vote
1
answer
86
views
Simple QisKit circuit seems to return incorrect statevector?
I have below a very simple circuit that initializes 2 qubits, and then saves the statevector. I cannot figure out why the simulator returns a vector of all 0's for the statevector. I'm using an older ...
- 111
0
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0
answers
207
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optimizing the circuit depth of a quantum circuit while using Fake Hardware
I am trying to search some ways in qiskit==1.0 to reduce the circuit depth while using Fake HW.
What I understand is that changing the optimization level to 3 will ...
- 219
1
vote
1
answer
65
views
Probable bug in DumpMachine() Quantum API function of Microsoft Quantum Platform
According to help from Microsoft Learn, the binding of Qubit[] array to its equivalent ket vector representation is such that the qubit with index 0 becomes the ...
2
votes
0
answers
77
views
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 ...
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1
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0
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28
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Is mcsolve from QuTiP Optimal for Solving Large Systems in the Lindblad Master Equation?
I am transitioning from using Mathematica to Python for my work on quantum systems, specifically focusing on solving the Lindblad Master Equation. For this purpose, I've started using the mcsolve ...
1
vote
2
answers
129
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Why does quantum circuit need to be run even though the probability is already in the formula?
In classical computing, it's clear by intuition why we need to run a program code to check whether a large odd integer number is prime or not.
It can be computed manually for such large number, but of ...
1
vote
1
answer
59
views
Noisy expectation value of non-Pauli observable in qiskit
I would like to calculate an expectation value of a general operator in a noisy simulation with qiskit.
The usual way of doing this is via an Estimatorwith a noise ...
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0
votes
1
answer
86
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Can quantum computers eventually be programmed "normally"?
They tell us that eventually quantum computers will break all current encryption methods. On the other hand, current quantum computers are programmed at a very low, mathematical level and for very ...
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0
votes
1
answer
59
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How to program Grover's Operator?
I understand the theory behind Grover's operator but I still am unsure how to code it. I have a quantum circuit with 13 qubits. Could someone please tell me step by step the code to use for Grover's ...
1
vote
1
answer
29
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Unexpected behavior of trapped ion's motional mode (phonon) heating simulation
I'm a novice at qutip simulation.
I was recently trying to use qutip to simulate the heating effect of a trapped ion by defining a jump operator defined with heating rate.
Below is the code of my ...
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0
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0
answers
19
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How does amplitude amplification work (in Grover's Algorithm) and does this code for it work?
I understand amplitude amplification at a high level: operations and gates are applied to the qubits such that the solution states amplitude is raised while the non-solution states are lowered. ...
0
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1
answer
51
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To output syndrome measurement results
May I ask you a question about the following? GitHub - Infleqtion/qLDPC: Tools for constructing and analyzing quantum low density parity check (qLDPC) codes.
In the above code, is there any code that ...
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3
votes
0
answers
40
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Transpilation error: CircuitError: 'The amount of qubit(0)/clbit(0) arguments does not match the gate expectation (2).'
I am trying to implement a algoritm that reduces the number of qubits required for MAXCUT optimization. I need to create a custom gate that encodes a diagonal unitary matrix where the diagonal ...
- 41
0
votes
1
answer
71
views
Uniformly sampling a random 3 qubit clifford gate
I try to uniformly sample 3 qubit clifford gates and apply them to my circuit. I'm using python language. I'm following this paper https://arxiv.org/abs/quant-ph/0406196 (Supplementary Materials 1....
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1
vote
0
answers
40
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Applying 2-qubit noise to a multi qubit system using local operations in Python
I am trying to create a simulation of 2-qubit dephasing noise that acts on the first two qubits of a multi qubit system. I would like to do this locally rather than expanding my kraus operators into $...
2
votes
1
answer
66
views
eigenstate is missing in the solution of vqe.compute_minimum_eigenvalue API in qiskit==1.0
I am using an API result= vqe.compute_minimum_eigenvalue using different version of qiskit. The qiskit==0.46 gives ...
- 219
1
vote
1
answer
81
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Getting negative probabilities in the count result
I am struggling with a very basic concept.
What exactly is the negative probability means in count result?
When I run a circuit without error mitigation and with error mitigation using a really great ...
- 219
2
votes
1
answer
533
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Substitute for QuantumInstance in latest qiskit==1.0
I have a old version of qiskit==0.46 code which uses the below syntax:
...
- 219
0
votes
2
answers
73
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qiskit.exceptions.QiskitError: 'Invalid input data for Pauli.'
I have some old version qiskit==0.46 code which uses an API as below:
...
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1
vote
1
answer
122
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Using statevector in latest version of qiskit==1.0
I am trying to use migrate my code from old version of qiskit to the latest version qiskit==1.0 for the statevector.
...
- 219
0
votes
1
answer
80
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qiskit.providers.basic_provider.exceptions.BasicProviderError: 'basic_simulator encountered unrecognized operation "ucry"'
I need some help in running circuit on qiskit==1.0 simulator.
The documents says:
https://docs.quantum.ibm.com/migration-guides/qiskit-1.0-features
...
- 219
0
votes
1
answer
33
views
AttributeError: Options field max_parallel_threads is not valid for this backend
I am working on migrating my code to the latest version of qiskit==1.0. Below is a part of my code:
...
- 219
2
votes
1
answer
154
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AttributeError: 'QuantumCircuit' object has no attribute 'ucry'. Did you mean: 'cry'?
I am trying to update my code to latest version of qiskit==1.1.1 Earlier we used to have a gate called as qc.ucry, but now I am ...
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