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. As of August 2020, there are 20 processors on the IBM Q Experience ranging from 5 to 53-qubits. Note: Some systems are only available to hubs, partners, and members of the IBM Q network.

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Cannot Repeat HHL Result [closed]

There is an HHL example in IBM Qiskit https://qiskit.org/textbook/ch-applications/hhl_tutorial.html If I run on that website (click "Try") in Section 4 and set ...
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Understanding the heavy output problem

In this paper (or more pedagogically here) it is given a way to compute the Quantum Volume of a quantum computer (qc), specifically aimed at the IBM qcs. In all this process I found some dark spots ...
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What is the actual precision of the IBM quantum computer?

In working with the IBM quantum computer, one can use for example the composer in order to build simple quantum algorithms. Essentially, one usually feeds a phase in order to affect one of the qubits. ...
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Can I use Quantum lab during IBM Quantum certification exam? [closed]

Hello I am about to take the IBM Quantum Qiskit dev exam. I don't know if I can use the quantum lab (Qiskit) during the exam. Does anyone know?
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Characteristics of the IBM quantum computer

On the IBM Quantum Composer website, there are characteristics of qubit computers. For example, ibmq_16_melbourne. But there is no description anywhere of what: ...
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1answer
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Recover backend information in working remotely with the IBM-QC

I'm reading the details of qiskit following this paper (I know it's a little bit dated, but some things shown there should be in principle still accessible). For ...
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68 views

Why is a 15-qubit IBM quantum computer not working correctly?

I just wanted to implement an algorithm for adding two 2-bit binary numbers. And it works, but only on an IBM 32-qubit simulator. And on a real 15-qubit computer, ibmq_16_melbourne, it produces very ...
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How to create a unitary gate using normalized complex numbers in qiskit?

If I have a normalized $(\alpha,\beta)$ as $(0.24506+0.9633i,0.0046238+0.10943i)$ for a qubit $\left| \psi \right> = (\alpha_1 + i\alpha_2 ) \left|0\right> + (\beta_1 + i\beta_2 )\left|1\right&...
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How call from IBM Q Experience (Jupyter Notebook) cplex

I have the latest version of cplex (12.9) installed on my computer. I use it very well with Jupyter notebook, but in IBM Q Experience, I did not get way to call it. IBM Q Experience warns me that the ...
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I can't see the results of my of my jobs

New user here. I tried to run a test circuit which I submitted to ibmq_santiago to run, but now I cannot see my results. No histogram, no circuit, only the status timeline. I believe the problem is ...
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Adding team to our IBM Quantum Experience account

I have an account and API token on IBM Quantum Experience (https://quantum-computing.ibm.com/) I would like to add team members to the account, so that everyone can use it without sharing login ...
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1answer
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Qiskit issues with Apple Silicon?

Edit/summary: Everything below this first paragraph is my original question posted several days ago and involves a lot of speculating on a problem I knew less about at the time. The purpose of this ...
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IBM Quantum: 20 minutes for 1 shot, timeout for 2 shots. Why? [closed]

It takes 20 minutes for the ibmq_qasm_simulator to execute 1 shot of my circuit. Successful always. It always times out for 2 shots of the same circuit on the same simulator. One may assume the ...
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What is a “barrier” in Qiskit circuits?

I just started studying IBM Qiskit, and cannot find details about the barrier method on the QuantumCircuit class. It is shown in the circuit drawing, but I never heard about it after reading quantum ...
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What's meant by the depth of a quantum circuit?

I'm using Qiskit to create quantum circuits wherein I've this attribute called depth. The documentation states it is the length of the critical path here. What does ...
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No backends assigned to my Account

When I open my account on IBM Quantum Experience, I am shown 9 backends that are assigned to me. But when I open any of my circuits, I get the error that "This account has no backends assigned&...
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1answer
60 views

What is the largest number factored by the IBM Quantum simulators?

Though a lot of papers talk about the largest factored number by Shor's Algorithm, I want to know the largest one factored by the IBM Quantum, for example, the simulator_mps. I am able to use it to ...
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1answer
58 views

How to upload our dataset using pytorch when it is not present in torchvision?

I am trying to upload my dataset(SWELL-KW) instead of MNIST in "Hybrid quantum-classical Neural Networks with PyTorch and Qiskit" provided by IBM qiskit but it says ...
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IBM Quantum “Jobs” web page problem: “Tags” always missing

I tried to edit the tags and saved them, but the "Jobs" page displays empty tags always. Is that a bug? Did I do it incorrectly?
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Bloch Sphere of Qiskit logo

Trying to plot the Bloch Sphere of the IBM Qiskit logo ...
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What is the minimal delay between gates on IBM devices?

Suppose I create the very simple circuit OPENQASM 2.0; include "qelib1.inc"; qreg q[1]; x q[0]; barrier q[0]; x q[0]; and submit it to an IBM backend. ...
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1answer
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API error when trying to access IBM Quantum Computer using IBMQ API Token

I'm trying to write a code so that if the token exists then it loads the account or else it asks the user for the API token. Below is the code for reference: ...
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1answer
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Please help interpret the IBM Quantum error code: “Instruction bfunc is not supported [7001]”

I have already run the circuit on the IBM Quantum simulators successfully. But, when I ran the same circuit on the real quantum device ibmq_16_melbourne, I got the error. The IBM website does have the ...
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What interesting properties can I measure with a 1 qubit state?

I am playing with the IBM Q and I would like to know what interesting properties I can measure with only a 1 qubit state. This is because things like Bell's inequalities, concurrence, PPT criterion, ...
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My IBM quantum account has been disabled

As shown in the picture above, my IBMQ account is unavailable, and I found that my friend's account is also unavailable, but I have not received any email or message notification. what happened?
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In the job tab, no histogram appears

(Newbie here) Accessing IBM Q Experience on a Windows 7 operating system and using the Google Chorme browser. I can completely assemble my circuit, using the IBM Quantum Composer and when executing it ...
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Process 3 MB of data in IBM

How can I process a 3 MB csv file in IBMQ? The memory shows 433 MB. Is this the maximum file size that I can upload and process in IBMQ?
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How to read a Q sphere representation?

I'm trying to understand the Q-sphere representation of a 3-qubit system. I get that the 3-qubits are in a superposition of 2 different states. The first qubit (rightmost) is in a superposition of <...
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IBM Quantum Experience complains “Circuit needs at least one measure.” But, the circuit does have one!

I want to run this simple test on the IBM quantum computer ibmq_lima, but it complains about the measurement. As you can see, there is one "measure". The weird part is that it works if I ...
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1answer
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Uploading 20,000 lines of code to IBM Quantum Composer stalls

It is a simple 5 bit circuit, but it has 20,000 lines of QASM code. I try to put it in the composer, but the "Saving..." beside the file name will stay there for hours. I never saw its ...
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1answer
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Why I am not getting approximate equiprobable states in the following circuit on IBM Q simulator?

I have the following circuit which consists of symmetric modules. I compiled the circuit in IBM Quantum experience backend - ibmq_qasm_simulator, 8192 shots. The result is not equiprobable. Why? Since ...
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1answer
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Error 400 on submission request on job that ran before

since today in the morning I am always getting the following error while running a job on IBM Sydney "'Error submitting job: '400 Client Error: Bad Request for url: https://api-qcon.quantum-...
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How do I get the names of all currently available IBMQ devices?

How do I get the names of all currently available IBMQ devices?
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JSONDecodeError with backend.run

I'm trying to follow tutorial on pulse simulation described in qiskit.org. The generated PulseQobj is well executed with AER simulator, but it throws JSONDecodeError when using real backends (ex. ibmq-...
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Running Qiskit Circuit Composer locally on Jupyer Notebook

I was wondering if I could use Qiskit locally on Jupyter Notebook and thus loaded my IBM-Q account via API token. I could construct circuits execute jobs but when I tried to use circuit composer, it ...
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How to initialize a qubit with a custom state in Qiskit Composer

I'm trying to initialize a qubit with a custom state in IBM's Qiskit Composer. I wrote the code in the Qiskit Lab and obtained the QASM code as shown below ...
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Is there a physical definition of barrier operation in qiskit?

As far as I know, we can use barrier method in qiskit to split circuits into two sets to prevent the optimization. However, is there any physical meaning of the barrier? Like a delay operation or ...
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1answer
40 views

Syndrome showing unexpected results for the [5,1,3] QEC code in qiskit

I have used the encoding procedure mentioned on page 35 of https://arxiv.org/pdf/quant-ph/9705052.pdf for the [5,1,3] code and then built the circuit for measuring the stabilizers (XZZXI, IXZZX, XIXZZ,...
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Memory Requirements for Qiskit Aer Simulator

I'm trying to work out how much memory is used for simulations of different sizes using the Aer simulator. Here are my calculations: $$ \text{Number of Qubits} = n $$ $$ \text{Number of Amplitudes} = ...
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On the IBM-Q experience, how do different frequencies for different qubits affect results?

I've been looking at the graphs of various Quantum Processors on IBM-Q experience and for qubits, frequency of different qubits is the first statistic shown. From this in the Qiskit textbook: The ...
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How do we implement QKNN algorithm on our dataset

What could be the steps to implement a distance based classifier (eg Qknn) on our dataset using quantum computing? I read a paper on "Distance based classifier using Iris dataset". I wanted ...
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How to do a POVM measurement of a quantum state in IBM's Quantum Composer?

I'm new to IBM, so I'm still figuring things out. I want to make a POVM measurement of a quantum state for state discrimination purposes. In other words I want a measurement that has three outcomes: A:...
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2answers
368 views

Does IBM have a publicly available tutorial on applied quantum computing and how does one use it? Any Reviews of the Tutorial?

I found this link and I am wondering if anyone has used it to learn or develop applications? I would like to know if people find it worth the time. I am reading the material by the way. https://...
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1answer
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How to make a half adder for x number of qubits with min. cost?

How to make a half adder for N inputs and getting the output on another x+1 output. Where x ...
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Can I run Cirq on IBMQ?

Google's quantum computer is not yet available for the public. Is it possible to run Cirq on IBM's quantum computers, instead of Qiskit? And if so, how can I do it? Thank you!
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How do I Initiate with my own alpha and beta values instead of starting form qubit in state zero in IBM Q?

Let's say I have normalized values of $\alpha$ and $\beta$ as $\alpha =(0.27524094128159016+0.8257228238447705j)$ $\beta =(-0.22019275302527214+0.4403855060505443j)$ How do I initialize my circuit ...
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3answers
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Is it possible to see the probabilities values of qubit ( alpha and beta) while measuring on IBM Quantum experience?

Is it possible to see what are the values of $\alpha$ (probability of being in state zero) and $\beta$ (probability of being in state one) while running on IBM Quantum simulator (we can call it state ...
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1answer
134 views

How to obtain the density matrix using tomography in the real device?

I am trying to run the QFT algorithm for n=5 (n number of qubits). The number of experiments that it generates is bigger than the one allowed by the IBM devices (i.e. 75). Therefore, I have tried to ...

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