Questions tagged [ibm-q-experience]
Use this tag for questions about IBM's Quantum Service - Circuit Composer & Quantum Lab. DO NOT use this for questions about general Qiskit issues (use [qiskit] for that).
489
questions
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2answers
40 views
Are we using the real-time error information in simulating noise on qasm?
I'm trying to run some quantum circuits on qasm simulator using the noise information from IBM Q quantum device:
...
3
votes
1answer
39 views
Where does the "correction" in quantum error correction occur, specifically when using repetition codes?
I'm reading the part of the qiskit textbook that deals with this (https://qiskit.org/textbook/ch-quantum-hardware/error-correction-repetition-code.html) and so far it seems as though they're just ...
1
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1answer
59 views
How to apply gates based on a random decision on the IBM quantum computer?
I want to run a circuit on an IBM quantum computer, and this circuit involves gates that are either applied or not based on a (classical) random decision.
As a minimal example, imagine a circuit with ...
3
votes
0answers
18 views
Do individual qubits on IBM quantum processors share the same control unit?
I want to investigate the maximum possible parallelism of quantum operations on a specific IBM device (such as the latest heavy-hex architecture), which requires a basic knowledge of their control ...
2
votes
1answer
78 views
Is there a faster way to do real-time error mitigation in qiskit?
I'm working on the readout error mitigation on a set of results obtained from different quantum circuits. The method I want to apply is to generate the confusion matrix for each quantum circuit (as ...
0
votes
1answer
69 views
Error when running a VQE circuit in IBMQ backends
I want to run a VQE circuit of 4 qubits for a simple Hamiltonian with Qiskit. The circuit run smoothly in simulators. However, when I try to implement it on real IBM' quantum computers it gives me the ...
1
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1answer
37 views
Can I use `job_manager` to get memories for 3 parts of the experiment?
Here's part of the code I'm working on:
...
2
votes
1answer
78 views
What is difference between qasm_simulator and ibmq_qasm_simulator?
There are many ways how to simulate a quantum circuit on IBM Q. However, in partiuclar I am interested in a difference between qasm_simulator and ...
2
votes
1answer
68 views
Quantum state inconsistency between book and IBM quantum composer
$
\newcommand{\ket}[1]{|#1\rangle}
\newcommand{\tens}[1]{%
\mathbin{\mathop{\otimes}\limits_{#1}}
}$I'm trying to self-learn quantum information basics by reading Dancing with Qubits by Robert Sutor....
2
votes
3answers
438 views
Are these two circuits equivalent in performing controlled time-evolution?
I want to perform the controlled time-evolution of some 2 or 3-qubit Hamiltonian. Say we have this example:
$$
H= Z_0\otimes Z_1 + Z_1\otimes Z_2
$$
The circuit performing the time-evolution ...
0
votes
1answer
41 views
How to execute a qiskit circuit from strangeworks hub? [closed]
I would like to execute a circuit in the strangeworks hub on IBM's "ibm_nairobi" system.
Could someone just please send me a general layout of execute and provide a command for stangeworks ...
2
votes
3answers
111 views
Saving statevector on more than one location in a quantum circuit in Qiskit
So, I'm fairly new to Qiskit, and I've been playing around and following the tutorials from the Qiskit textbook. However, there is one thing I fail to understand/implement: for a quantum circuit with ...
2
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0answers
56 views
How can I add custom pulse gate to the Qiskit circuit?
I tried to make my pulse and get the pulse into the circuit. But it seems not working properly.
The code and the result are below.
Just change the 'x' to the 'h' (hadamard) with the same piecewise ...
2
votes
1answer
99 views
HHL - the result is correct for one matrix but wrong for another one
I tried to run HHL algorithm in new version of Qiskit (0.29). Firstly I tried to solve a diagonal system 4x4 with matrix [[1,0,0,0],[0,2,0,0],[0,0,3,0],[0,0,0,4]] ...
4
votes
2answers
188 views
Cannot get a provider from IBMQ
My code is:
from qiskit import IBMQ
IBMQ.load_account()
provider = IBMQ.get_provider('ibm-q')
qcomp = provider.get_backend('ibmq_16_melbourne')
but ...
1
vote
1answer
69 views
Simulating OpenQASM 2.0 in Qiskit?
I'm just getting started with OpenQASM, but I'm feeling a bit confused. Is there a way to run the .qasm file I've written in Qiskit (i.e. in Python), or is OpenQasm ...
6
votes
1answer
209 views
What is the basic hardware gate library in the IBM & google?
I need to know what is the basic hardware gate library in hardware IBM and Google? I mean, which one of the gates can be implemented directly in the hardware. I would be very grateful if everyone ...
1
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1answer
70 views
Can I extract information from a single shot efficiently?
I'm running a quantum simulation and want to obtain some information from a single shot of an experiment. Here's part of the code I'm working on:
...
2
votes
2answers
127 views
IBM Quantum: Are ibmq_5_yorktown and ibmqx2 different devices?
When I run provider.backends(), ibmqx2 is listed as an available backend, but is not listed on the IBMQ systems page. This file ...
4
votes
1answer
216 views
Do I need to use classical bits in measurement?
I wonder if I have to add classical bits while performing measurement for a single-qubit quantum circuit. The difference to initialize the circuit is ...
4
votes
1answer
76 views
Measure $\langle \hat{X}\rangle$ and $\langle \hat{Y}\rangle$ from counts
I'm confused about how I can measure $\langle \hat{X}\rangle$ and $\langle \hat{Y}\rangle$ using counts. Here's my code for X:
x-basis:
...
0
votes
1answer
57 views
This is a question about IBM quantum circuit used to generate the quantum cheque state
I'm learning about quantum cheque. And I read "Experimental realization of quantum cheque using a five-qubit quantum computer" which is written by Bikash K. Behera ,Anindita Banerjee and ...
2
votes
2answers
87 views
How to Implement a noisy identity gate on qiskit?
I can successfully implement the U gate (single qubit) on qiskit, but when I am trying for the identity operation it is not showing any differences with the ideal one .
1
vote
1answer
42 views
Job ids retrieval from ID. Big set of jobs
I'm in the need of running a lot of jobs in the IBM backends. If one likes to run in parallel two jobs (say, with two different parameters), I have seen in the Jobs ...
0
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1answer
31 views
What are the runtimes of the different modes of qiskit's mcx?
Qiskit's mcx has four different modes:
'noancilla': Requires 0 ancilla qubits.
'recursion': Requires 1 ancilla qubit if more than 4 controls are used, otherwise 0.
'v-chain': Requires 2 less ancillas ...
3
votes
0answers
62 views
"503: Server Unavailable. Your server appears to be down. Try restarting it from the hub". Help
This message is popping continuously for 2 days in my IBM Quantum lab. I have tried logging out and in again, restarting the browser, changing the internet connection, and changing the device but this ...
2
votes
0answers
48 views
Does dedicated mode provide better results than fairshare in mid-circuit measurement?
I'm using a research account and I have a question about running circuits with (dedicated/priority mode) and without reservation (fair-share mode). From the documentation of dedicated mode,
This (The ...
0
votes
1answer
61 views
Measuring the accuracy of a circuit output?
I have created a circuit and got the output which matches the truth table but, I'm not understanding the measuring the circuit output in terms of the probabilities, power or error.
This is the circuit ...
1
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1answer
48 views
Why the last IBMQ job of my VQE have just one circuit?
I am running a VQE over the H2 molecule on ibmq_quito and I set a callback function to save all jobs id's of all iterations. When I check the penultimate job (and the previous ones), I have 2 circuits ...
1
vote
2answers
87 views
Random accuracy using VQC and Iris dataset
Using the same seed (seed_simulator and seed_transpiler) I get different accuracy when running it several times.
In Aqua library (from qiskit.aqua.algorithms import VQC) I solved it adding ...
1
vote
1answer
94 views
How to download from IBM Quantum lab folder of data .txt files all at once?
I have a script in the IBM Quantum lab which runs several jobs and stores the result of each job as a .txt file in a results folder. All I want to do is to download the folder of files. I cannot ...
1
vote
1answer
56 views
how can we save a model using qiskit_machine_learning?
How can we save a trained model using Qiskit Machine Learning library?
I've built a VQC classification model and once finished, I'd like to save the different models to be loaded later.
There is a <...
2
votes
1answer
28 views
Adding collaborator to project during reservation
If I add a collaborator to an IBM Quantum Education project during a system reservation, do they immediately get priority access to the reserved system? Or do I need to add them before the ...
0
votes
1answer
91 views
How to build and visualize circuit from matrix?
In paper Efficient quantum algorithm for solving travelling salesman problem: An IBM quantum experience, the authors use gate $U_j$ and its decomposition
$$
U_j =
\begin{pmatrix}
\mathrm{e}^{ia} &...
1
vote
1answer
62 views
Trying to connect IBM Quantum to External API
Is it possible to connect a quantum computer to openlibary.org API? How do I find the public IP address to my quantum instance?
0
votes
1answer
50 views
How can I simulate the Avg CNOT Error on IBMQ Backends?
I want to know exactly how to estimate the Avg CNOT Error rate for IBMQ Backends?
For instance, I tried to estimate the Avg CNOT Error rate for Belem Backend; I randomly prepared the 00,01,10,11 ...
0
votes
1answer
42 views
FileNotFoundError: No such file or directory. This error occurs while giving a data path to upload datafile(present on desktop) in IBMQ
I am trying to implement https://qiskit.org/textbook/ch-machine-learning/machine-learning-qiskit-pytorch.html#3.-Let's-code!- in IBMQ using a dataset present on my desktop.
While uploading a dataset ...
-1
votes
1answer
33 views
What is this pulse experiment showing?
The following results in the figure were achieved using Qiskit pulse by doing the following pulse sequence;
{ $\frac{\pi}{2}$, delay $\tau$, $\pi$, delay $\tau$, $\frac{\pi}{2}$}
The figure is the ...
1
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0answers
34 views
Recover qubits used in an actual computation
How do I recover from a certain job_id in the IBM backends which qubits where used?
I would be interested to know if for instance, in a batch of say 50 jobs, 25 of ...
2
votes
1answer
92 views
How to find the expectation value of several circuits using Qiskit aqua operator logic?
I am using the method from this SE answer to calculate the expectation value using qiskit aqua operator logic which works well for a single circuit. Here is a simplified code snippet to demonstrate ...
3
votes
1answer
86 views
When will Qiskit Runtime be available to all users?
IBM's Qiskit Runtime was recently made available to a select group of users. Have they announced when it will be available to all users or when they might open it back up to a second round of new ...
2
votes
1answer
75 views
IF statement in OpenQASM2.0 on IBM Quantum Experience -- error
I have written the following toy .qasm file, which has some adaptive measurements:
...
3
votes
1answer
125 views
How do I identify a VQE job run in real hardware?
I am running a VQEUCCFactory for H2 on a real hardware device.
...
1
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1answer
95 views
Guide for Qiskit's Measurement Error Mitigation?
I'm reading about error correction mainly in the Qiskit Measurement error mitigation chapter contains what it seems and easy way to "clean up" the noise obtained in the IBM (or NISQ) devices....
3
votes
1answer
167 views
How do I send a quantum circuit to IBM for execution?
I have, let's say, the following quantum circuit:
The QASM code of this quantum scheme has the following form:
...
6
votes
2answers
273 views
Apply readout error mitigation to mid-circuit measurement
I'm trying to construct a quantum circuit with 3 mid-circuit measurements, here's an example:
...
2
votes
1answer
65 views
QPE Circuit test on Quantum Computer ('ibmq_16_melbourne')
After several atempts, I cannot mitigate the error when running the code on a NISQ, via the qiskit library (more specifically on the 'ibmq_16_melbourne').
I've already mapped the connected qubits and ...
3
votes
2answers
383 views
How can I specify the qubits on quantum computers that I want to use?
Suppose I have the following 2-qubit quantum circuit:
...
2
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1answer
28 views
"us" units on relaxation times $T_j$ in the IBM backends
A pretty lame question but, the backends relaxation times $T_1,T_2$ are given in us units. What are those? (Frequencies are given in GHz... Is it really $\mu s$ but IBM can't display the $\mu$ in the ...
1
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1answer
79 views
$T_1/T_2$ thermal relaxation example
The built in noise models in Qiskit have an example of $T_1/2T_2$ relaxation here. I have a couple of doubts; the notebook is not very clear in some of the steps.
Why does one need $T_2\leq 2T_1$? ...