Questions tagged [ibm-q-experience]

Use this tag for questions about IBM's quantum processors which are accessible online. DO NOT use this for questions about general Qiskit issues. As of July 2018, there are five processors on the IBM Q Experience: two 5-qubit processors, one 16-qubit processor and two 20-qubit processors (only available to hubs, partners, and members of the IBM Q network).

Filter by
Sorted by
Tagged with
4
votes
2answers
99 views

How to implement the CCH gate in quantum computers available in clouds?

How to implement CCH gate in quantum computers available in clouds? If there is not any gate directly available for it, what are the possible ways to represent CCH?
4
votes
1answer
136 views

What is the state of the art on Quantum Random Access Memories? [duplicate]

I realized that Quantum Random Access Memory (qRAM) was proposed to make quantum computers more similar to classical one. Currently quantum computers have very constrained memory, given only quantum ...
2
votes
2answers
142 views

Qubit measurement is followed by instructions. Error code: 7006 [duplicate]

Trying quantum teleportation in https://github.com/Qiskit/qiskit-textbook/blob/master/content/ch-algorithms/teleportation.ipynb Succesful runs in 'qasm_simulator', but when switching to IBMQBackend('...
3
votes
1answer
218 views

Cannot replicate results in article on pricing financial derivatives on IBM Q

I am trying to implement a circuit for searching for the largest eigenvalue and respective eigenvector of an operator, i.e. phase estimation, introduced in article Towards Pricing Financial ...
7
votes
2answers
1k views

Changing one qubit causes changes in another independent qubit on ibmqx2 in IBM Q Experience

When I run this program on ibmqx2 (the backend matters) in IBM Q Experience, the results are interesting. Essentially, the program measures the error rate on $|q_0\rangle$ after fiddling with $|q_1\...
3
votes
1answer
67 views

Writing twice to same classical register -> 1 for some backends in IBM Q Experience

On some backends, measuring the same expected value twice to the same classical register always leaves that classical register in the "1" state. I don't know if these results will hold over time, but ...
5
votes
1answer
154 views

Reversal of time arrow on IBM Q

It is well known that a quantum computer is reversible. This means that it is possible to derive an input quantum state $|\psi_0\rangle$ from an output $|\psi_1\rangle$ of an algorithm described by a ...
2
votes
2answers
106 views

Simple program produces consistently skewed results in IBM Q Experience

I'm running this program (essentially a two bit random number generator) on ibmqx2 in IBM Q Experience. The backend matters. Other machines give unexpected results, but the graph looks different for ...
3
votes
2answers
102 views

Why IBM devices have the same number of qubit and the same architecture, but the error rates are different?

Here are two different IBM quantum online devices, Both of them have the 5 qubits and the same architectures. But why do they have different error rate? What's the different between them?
2
votes
1answer
134 views

How to plot histogram or Bloch sphere for multiple circuits?

I have tried to plot a histogram for the multiple circuits for the code given below. I think I have done it correctly but don't know why it's not working. Please help me out. If possible please solve ...
0
votes
1answer
151 views

run() got an unexpected keyword argument 'seed'

I am new in quantum computing. I was going through the user guide of IBM Q so I was just trying to run the python code they have provided at the end of this page enter link description here while ...
1
vote
1answer
64 views

Job Status: job incurred error

I was checking the limits of shots in IBMQ at the time of execution of the circuit so I was getting this error message Job Status: job incurred error at ...
1
vote
1answer
117 views

Why qiskit superconducting device native gates different from that of trapped ion device?

For IBMQ device based on superconducting technology, when we transpile the circuit, it is decomposed of U1,U2,U3 and CNOT gates, which are its native gates. However for trapped ion device, its native ...
3
votes
1answer
124 views

Custom gates on IBM Q

I realized that QASM supports custom gates. However, when I tried to create the gate, transpiling error appeared both on simulator and real quantum processor. I suspect that IBM has not implemented ...
1
vote
1answer
330 views

How to fix an error: AttributeError: 'IBMQFactory' object has no attribute 'get_backend'

when I tried to execute task in "Jupiter notebook" in the IBM Q experience (the browser), ...
-2
votes
1answer
34 views

How does number of shots (number of times the computation is repeated) affects time complexity [closed]

I want to know what happens to the time complexity in terms of big O analysis
0
votes
1answer
86 views

QISKit Connection

I ve beeen trying to use the qiskit package from spyder IDE inisde anaconda (Python version 3.7) but when i try to acces my account I get the following error: ...
1
vote
1answer
100 views

IBM Q experience - error code 520

I have been running a variational circuit optimizing the parameters on the "melbourne" device. The system launches multiple jobs in parallel, and only gets the jobs accepted that my credit allows. The ...
0
votes
1answer
57 views

Find the Q-Experiment tutorial for beginner

Where I can find the previous Quantum-Experiment tutorial for beginners? (the one that was under https://quantumexperience.ng.bluemix.net/qstage/#/account)
5
votes
1answer
165 views

What does the error rate on the IBMQ website mean?

How is the error rate pointed by the arrow defined? How did you get it? thanks!
0
votes
1answer
67 views

What can be done so far with cloud quantum computing?

As a developer myself, I still do not understand what can be done so far with services like AWS BRAKET or IBM CLOUD QUANTUM COMPUTING. Can someone explain me the practical purpose of it in the present?...
2
votes
1answer
83 views

Is there a way to output a circuit from Qiskit to the IBM Q Experience circuit composer?

I can't seem to find anything, but this seems like something that should be possible.
1
vote
0answers
63 views

Ripple Adder using Full Adder [closed]

I have been trying to implement a ripple carry adder using qsikit in IBM Q Experience. I was able to implement full carry adder but I am having trouble with ripple carry adder. I am able to add 100 + ...
1
vote
1answer
94 views

Can't access IBMQ (NameError: name 'IBMQ' is not defined)

When I type this: IBMQ.load_account(), I am getting this error. What does this mean, and how can I rectify it? ...
2
votes
1answer
142 views

Couldn't connect to IBMQ server

When I access IBM Q backend with qiskit code, an error occurs. from qiskit import IBMQ qt = 'xxxxxxxxx' IBMQ.save_account(qt) IBMQ.load_accounts() The error ...
3
votes
1answer
137 views

How to put a quantum computer on the cloud?

What are the infrastructures needed to build a cloud quantum computing service like IBM Q Experience? It seems this is not a trivial task. IQX has been running for more than 3 years and yet it is ...
0
votes
0answers
47 views

What is the URL of the result?

This answer states that: Once it is submitted, your job will be in queue. You will have to request by GET this job ID to get the answer from the backend. The GET URL is: https://quantumexperience....
3
votes
2answers
366 views

Explanation of output produced by the following quantum circuit

I've recently started reading about quantum computing and I apologize in advance if this is (and I think it probably is) a very simple question. I've created the following circuit. I believe I ...
-4
votes
1answer
79 views

Bernstein-Vazirani algorithm in IBM Q Experience [closed]

I have composed the gate with IBM Q Experience, but I do not know how to set the answer. Please tell me how to set it?
4
votes
0answers
40 views

Vary parameter between shots

Is it possible to tell Qiskit to execute a parameterized gate where the parameter varies between shots? Let's say, for whatever reason, I'd like to speed up the dephasing of a qubit during a run. I ...
1
vote
1answer
42 views

qiskit - Creating your own ExperimentResultData object

Could someone guide me on how to create my own qiskit.result.models.ExperimentResultData object? I would simply like to create an object with some self-created dict ...
1
vote
1answer
31 views

Data file read/write from within IBM Q-Experience Jupyter notebook

In IBM Q-Experience how can I upload a data file that I intend to read from the python code?
-1
votes
2answers
68 views

Bell state: simultaneous measurement of two entangled qubits

What will happen if the two qubits in Bell state for a 2-qubit system, $\frac{1}{\sqrt2}(\left|00\right\rangle+\left|11\right\rangle)$ are simultaneously measured at the same instant? Two scenarios: ...
-3
votes
1answer
84 views

How to get more credits? [duplicate]

How can I have 150 or more credits? I mean I want to have '150/150 credits'.
0
votes
0answers
30 views

IBM Circuit Composer pane is blank

I'm new to IBM Quantum Experience. When I initially create a circuit using the composer, all is well, but when I save the circuit and open it again, the composer window is blank - no gates or wires. I ...
0
votes
0answers
37 views

Implementing B92 protocol on IBM Qx

I wanted to implement the B92 protocol on IBM Qx. Implementing the protocol would require that a particular qubit should not be measured when using a particular base i.e. there should be no output at ...
1
vote
0answers
55 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,...
2
votes
0answers
22 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 ...
4
votes
2answers
629 views

Trying to build a circuit for quantum teleportation on IBMQ I get ERROR_RUNNING_JOB error

I am trying to build a circuit for quantum teleportation. On the simulator, everything runs fine and according to expectations, however, I am not able to run the algorithm on the real quantum ...
3
votes
0answers
112 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 ...
1
vote
1answer
131 views

Attribute error in Qiskit

Tried executing plot_histogram(result.get_counts(circuit)) where result has the job result and circuit is the Quantum circuit But an attribute error hits every ...
2
votes
1answer
53 views

Existing measurement error mitigation

Does IBM compute a measurement error mitigation calibration matrix that can be accessed from its device properties or somewhere else? Or does the user have to do that every time?
2
votes
1answer
85 views

Error on loading account with qiskit: “TypeError: __init__() missing 1 required positional argument: 'url'”

We are using an open account. We can not load the account even when we use the code on new notebook. The error message is: ...
4
votes
1answer
140 views

How to parallelly run a quantum circuit on IBMQ?

I am trying to implement the following circuit and my code is The above circuit has size 5 and depth 3. My question is, how can I run the circuit parallelly. I mean, the gate ...
2
votes
3answers
125 views

IBM 53 qubit cloud access

IBM announced a 53 qubit chip. Will the advertised chip be available for non-paying users, or only to IBM clients?
2
votes
1answer
52 views

Is IBM Q composer using little-endian representation for multi-qubit states?

I am still confused when I am trying to use the IBM Q composer to reproduce some quantum circuits I found in different papers, and I am wondering if it is because there are two ways to represent a ...
1
vote
0answers
42 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 ...
6
votes
1answer
920 views

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 ...
-1
votes
1answer
71 views

What is ''524 Server Error''?

When running my code, sometimes I find this 524 Server Error: Origin Time-out for url and then my code stop. The error is in ...
4
votes
0answers
505 views

Is it possible to run a general implementation Shor's algorithm on a real IBM quantum computer at least for N = 15?

I need to make a general implementation of Shor's algorithm that factors, at least, N = 15. I have been able to perform an implementation that works in simulators, with ProjectQ, but when running it ...