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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6
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1answer
440 views

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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39 views

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 ...
4
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0answers
93 views

Form and effect of the intrinsic Hamiltonian on the IBM machines

I want to understand the form of the intrinsic Hamiltonian of the IBM machines, such as ibmq_16_melbourne, and how this affects the data I get out when waiting ...
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0answers
214 views

Problem with measurement error mitigation using VQE

I am attempting to mitigate measurement error while running on one of IBM's real devices and am doing so by passing CompleteMeasFitter into ...
4
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0answers
119 views

Results from looped experiments on IBM Q different than individual experiments

I'm experiencing an issue while using Qiskit where the counts from a job return vastly different values when ran in a loop or as an array of circuits as opposed to single experiments when run by ...
4
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0answers
92 views

IBM Q devices' hardware/resource constraints

I tried to look for the resource constraints but so far haven't been able to find them. They are not present in the GitHub repository that usually provides the hardware information for the different ...
4
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86 views

Implementing a depolarizing channel for 2 qubits on IBM Q

I am trying to use IBM Q to perform the following depolarizing channel on a state of 2 qubits $\rho=|\psi \rangle \langle \psi |$: $$\rho \to (1-\lambda)\rho + \frac{\lambda}{4}I$$ This is within ...
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36 views

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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0answers
30 views

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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45 views

IBM QE - Parameters that differentiate the various backends

I'm doing a university thesis using IBM's quantum backends. In my analysis I am making some considerations on what differentiates one backend from another other than the number of qubits and quantum ...
3
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0answers
57 views

What is the best way to use loop statements on a quantum computer?

I am interested in solving a time dependent linear partial differential equation of the form $Ax=b$ which, in classical computing, would amount to looping over solutions of $Ax=b$ where $b$ is updated ...
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34 views

How many cores and what processors are used in the cloud ibmq_qasm_simulator?

Cloud IBMQ simulator ibmq_qasm_simulator can process up to 32-qubit circuits quite fast. However, I could not find any information about the simulator backend properties, e.g. how many cores, what ...
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100 views

Difficulty in implementing Grover's Algorithm with large number of qubits

It seems IBM offers a 15 qubit quantum computer through their quantum experience program. However, upon a quick search through the literature, the largest implementation of Grover's algorithm I have ...
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0answers
373 views

Measuring Coherence Length for T1 and T2 values with IBMQ Experience

So I'm currently working on a little program to measure how long the coherence time of a qubit is. Basically the idea is to initialise a qubit with a X or H gate then stick in a varying amount of ...
3
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78 views

Bell State 11 not working for parity curve

I am currently writing a script to automate the creation of parity curves for a 2 qubit bell state and then calculate fidelity and proving entanglement from that (inspired by this paper). It was going ...
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528 views

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 ...
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37 views

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:...
2
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1answer
70 views

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: ...
2
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1answer
270 views

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 ...
2
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1answer
42 views

Is Noise model for quantum prototypes accurate in Qiskit

We know that in Qiskit noise models modeling specific quantum machine prototypes exist and can be inserted into the code. However, are these models fixed in nature or they continuously improve ...
2
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1answer
46 views

Need mathematical Calculation of input(T1,T2,f) and output(Readout Error)

I would like to know about the mathematical relations among T1, T2, frequency, readout error, and single-qubit error? This screenshot is from the ibmq-16 Melbourne excel data file.
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0answers
53 views

What is the buffer time between gates of the ibmq_essex in nanoseconds?

This is a question that I asked on Qiskit ignis section of slack, with a very interesting answer by A Kapila, but I also need to get a short answer in nanoseconds. I want to evaluate decoherence in ...
2
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1answer
102 views

VQE jobs do not appear in queue

I am trying to calculate the ground state energy of some simple molecules using 'MolecularGroundStateEnergy' tools in qiskit. When I run the calculations for very small molecules (e.g. H2, HeH+) the ...
2
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1answer
96 views

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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0answers
32 views

Tensored vs ordinary measurement mitigation runtime

My experiments show that the runtime of actually applying the measurement filter matrices to circuit execution results is much slower for tensored mitigation than ordinary mitigation. Tensored ...
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0answers
97 views

Is it possible to simulate or replicate a cryptographic algorithm using Qiskit?

I would like to know if it is possible to recreate or simulate a cryptographic encryption algorithm like DES or AES using the quantum computing platform Qiskit from IBM?
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0answers
111 views

Running HHL tutorial on real backend

I tried to follow the HHL tutorial. Since the 8x8 problem is not realistically simulable (I stopped after a few minutes), I tried to make it run on another backend, starting on the easiest example: <...
2
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1answer
89 views

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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0answers
930 views

How to run quantum SVM algorithm from Qiskit in real IBM Quantum Computer using IBMQ?

I'm trying to run QSVM algorithm in IBMQ experience, want to run in one of those real quantum computers. ...
2
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0answers
418 views

How to measure a Bell inequality violation in IBM Q?

Note: Cross-posted on Physics SE. I made some circuit to prepare a 2 qubit state, but I am having trouble understanding how to measure Bell's inequality. I know the inequality is of the form $$|E(a,...
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29 views

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?
1
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1answer
72 views

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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0answers
59 views

Transpiler fails after 1000 iterations

I'm transpiling a set of quantum circuits using ibmq_5_yorktown. However, as the number of circuits gets larger, it shows me the following error message: ...
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0answers
74 views

State bug in IBM Quantum Experience

I run many tests with VQC and QSVM algorithms. In last times I can't get final result because some job hang on state Creating, Validating or Running. It can continue many hours and It doesn't finish. ...
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0answers
59 views

Length / transpilation issues with Grover's algorithm

I would like to discuss the discrepancies between what we see in the simulator versus what we see in the actual running of the code on any IBMQ machine for any qubits at 5 or above. I am doing a final ...
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0answers
38 views

qasm_simulator generating identical results repeatedly

I wish to run a very simple circuit on the qasm_simulator backend. My circuit is ...
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0answers
37 views

Report measurement components for a given Hamiltonian measurement

I was wondering if there is a possibility to report measurement components when reporting the final expectation values of a qubit operator. For example, if we look at a simple Hydrogen molecule ...
1
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1answer
143 views

Unable to instantiate provider for research account locally

When I run IBMQ.load_account(). I have the error information: ...
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0answers
46 views

What causes the random variations in the probabilities with respect to the theoretical values, in IBM and QASM simulators?

When I measure 2 and 3 qubits after putting H gate on all of them, there is a variation in probabilities of results in comparison with theoretical values (25% and 12.5%, respectively). This occurs on ...
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0answers
38 views

Post-selection in QASM

In some quantum algorithms (for example HHL or quantum machine learning algorithms) an ancilla qubit(s) is measured firstly and based on result of the measurement other qubit(s) are measured or not. ...
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0answers
62 views

ibmq_qasm_simulator from IBMQ provider and qasm_simulator from Aer provider gives different results

I'm running an experiment first on qasm_simulator backend from Aer provider and the most frequent result is the correct one with ...
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0answers
126 views

Error when running an algorithm on real device at IBM Q using QASM

I'm running an algorithm on a real quantum device from IBM (ibmqx2), using the QASM and circuit composer, and it just gets the same error over and over again: ...
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0answers
40 views

Meaning of “Running” time field in Results and correlation with the “shots” choosen number

I've created a same circuit that I've executed two different ways on the same computer (ibmq_16_melbourne); First with 1024 Shots and secondly with 8096 Shots For the first (1024), I got in results, ...
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0answers
48 views

How qubit phase is build in real hardware?

How qubit phase is build in real hardware? On IBM Quantum, D-Wave, etc?
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0answers
58 views

How can I run programs in test folder Github Qiskit

I am new to GitHub/Python - please tell me how can I run programs in https://github.com/Qiskit/qiskit-aqua/tree/master/test and its sub directories in Jupyter. I am connected to IBM Q Expereince. I am ...
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1answer
88 views

How can I find the fidelity of preparation?

I want to know the fidelity (or error rate) of the preparation of $|0\rangle$. How can I obtain it?
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0answers
35 views

Problem with circuit composer results tab

I'm trying to run a simulation of the following circuit: on the ibmq_qasm_simulator, but it only shows the "Circuit diagram" without the "Circuit Implementation" and "Results tab". Did someone had ...
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0answers
61 views

Many jobs hanging after creating

I am running a VQE calculation running from a cluster using nohup. However, some of my jobs keep hanging with 'creating' and therefore my VQE is not converging/not working. However, at the same time,...
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0answers
50 views

Transfer trained machine learning model

I know just the basics of quantum computer i.e. superposition, entanglement, gates and few other kinds of stuff. Now the question is it possible to transfer a trained machine learning model from IBM ...
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0answers
412 views

Job execution issue while using IBMQ Experience

I am trying to run QSVM algorithm on the IBMQ backend devices using the API_TOKEN. Below is the snippet of the code that I am running. The code fails the validation test and throws an exception after ...