Questions tagged [ibm]
For questions about IBM's quantum computing processors and devices. For their cloud-computing service use the [ibm-q-experience] tag instead.
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Good resources for seeing qubit control pulse shapes (Transmon qubits)
I'm looking for resources which can show the pulse shapes for various single-qubit and two-qubit gates.
More specifically, is there any resource which can show me calibrated pulse shapes so that I can ...
3
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1answer
71 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 ...
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1answer
66 views
Qiskit - lesson 3 - with Abe
Coding for Qiskit
I watched this video:
https://www.youtube.com/watch?v=RrUTwq5jKM4
Using Mac OS Big Sur
Using Jupyter 2.0.8
Using Python 3.8
The below code did not work and therefore installed ...
3
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1answer
151 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:
...
2
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1answer
67 views
IBM Quantum API for Java Developers
As far as I know, IBM Quantum provides two types of APIs: one for Qiskit, and the other for third-party uses (API for developers).
In this question, there are several arguments about using the API for ...
4
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1answer
75 views
CNOT error rate of 1 in IBM backends
I have noticed that some CNOT gates (for instance, between qubits 1 and 2 in ibmq_casablanca) display an error rate of 1 while typical error rates are of course ...
1
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1answer
69 views
IBM quantum computer giving the wrong result?
This is the first time I am using the IBM quantum computer. I tried to run a circuit (see below the first picture) but the results I got don't match the theoretical results shown (see below the second ...
2
votes
2answers
49 views
Who is responsible for implementing quantum error correction?
There are various options for error correction. For example, the Shore code or a whole class of surface codes.
But I don't really understand at what level they should be implemented.
For example, I ...
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0answers
65 views
Does a quantum computer exist today? [closed]
I agree that this may not be an easy question to answer.
But lately, I increasingly come across the fact that many news materials and research papers in the field of quantum technologies say that at ...
1
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1answer
60 views
Is there any way to obtain the number of qubits of a given backend in Qiskit?
I'm testing out a program in different IBMQ mock backends, and I want the program to use the maximum number of qubits in each case. Is there any function/method to extract the number of qubits of a ...
1
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1answer
56 views
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?
5
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0answers
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Optical quantum computers VS Superconducting quantum computers VS Electron-spin quantum computers
One of the main problems of superconducting quantum computers is that it is necessary to maintain a very low temperature (near absolute zero).
Such cooling is very expensive and complex.
Why, then, ...
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1answer
82 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 ...
7
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2answers
1k views
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:
...
2
votes
1answer
98 views
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-...
1
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1answer
54 views
Qiskit: 3 applications of identity with arbitrary SU(2) is universal?
We know that the CNOT gate together with arbitrary SU(2) gates can be used to perfectly implement arbitrary SU(4) gates with 3 applications of the CNOT.
I am using the Qiskit library and testing how ...
1
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1answer
85 views
Error while running Qiskit code on real quantum computer
I was trying to run this code on a quantum computer but I was getting an error can anyone suggest how to resolve this error?
...
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2answers
48 views
Multiple Providers on IBMQ
I am attempting to run parallel computations on two different backends from within the same Jupyter notebook, though it appears these two jobs are running sequentially. I understand the jobs will be ...
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1answer
47 views
processing between sequential executions
Regarding real quantum computers of IBM, can one execute a circuit that contains measurements and afterwards get counts and then, based on the results of measurements (from counts), decide if to build ...
2
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1answer
43 views
Is it possible to modify pulse schedules in QASM?
Is it possible to modify a pulse schedule of a circuit compiled using QASM? I know this is possible using OpenPulse, but it seems none of the IBM backends support OpenPulse. So is it possible to do ...
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3answers
102 views
How to create the state $\vert 0 \rangle+i \vert 1 \rangle$ using elementary gates?
I am trying to write $|0\rangle+i|1\rangle$ in terms of elementary gates like H, CNOT, Pauli Y, using the IBM QE circuit composer.
I was thinking some kind of combination of H and Y since $Y|0\rangle=...
2
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1answer
124 views
Can I access device specifications of IBMQ paying devices?
I need to perform some tests for my thesis in real quantum computers, however, I only have access to IBM's free quantum devices (the maximum number of qubits I can use is 15, in ...
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1answer
74 views
How to deal with job submission error in IBM? [closed]
I keep on getting this error no matter how many circuits I run in the backend 'ibmq_athens'. It says 'Max retries exceeded with URL'. Can someone explain why I am getting this error message.
The main ...
3
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1answer
132 views
Qiskit's c_if and conditioned operations on a real quantum computer
Can Qiskit's c_if be used on a real quantum computer of IBM? And if it can, can it put a condition only on Qiskit gates like X, H, U1, U2, etc, or is there some way ...
5
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2answers
269 views
Topology graphs of IBM's quantum computers
What is the meaning of the topology graphs of IBM's quantum computers? How should it be interpreted?
For example, how should I understand the following graph?
3
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1answer
49 views
Kernel stopping when solving water molecule ground state
I'm new to QISKIT Aqua and I'm trying to follow the Ground State tutorial to solve the Water molecule ground state, but when I execute the calculations the kernel stops.
I'm using IBM Q Experience ...
3
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1answer
62 views
Is every computer in IBM's fleet based on superconductivity?
I'm currently writing my thesis and I'd like to know which computer is based on a superconductive architecture to run some simulations.
Thanks for help in advance.
2
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1answer
55 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
87 views
Connectivity in Grover's algorithm on real quantum computers
Everytime I execute Grover's search algorithm on IBM real quantum computers I get a wrong answer (it doesn't find the correct winner state) unless I use only 2 qubits. For any higher number of qubits ...
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1answer
34 views
Mechanism of measurement in IBM quantum devices
I am trying to find out about the mechanism of measurement in IBM Q devices. To be specific, if I apply two Hadamard gates on the first qubit and identity on the second then is it possible to ...
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1answer
107 views
How to measure a quantum circuit's execution time on a real IBM device?
I am executing a quantum circuit on an IBM quantum device and I need to start a timer as soon as the job in the queue starts running. I have already used:
...
4
votes
1answer
90 views
IBMQ backends: How can I know the repetition rate and depth limits of real devices?
When trying to execute complex quantum circuits on IBMQ real devices, one can encounter a typical error (ERROR_RUNNING_JOB) with the message ...
2
votes
2answers
82 views
Is there a quantum processor with physically implemented Toffoli gate?
Recently, I came across the article Realization of efficient quantum gates with a superconducting qubit-qutrit circuit where its authors proposed a physical implementation of three qubits quantum ...
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0answers
135 views
Is there a good reason to use T-count minimization for circuits executed on current IBM open quantum systems (real hardware)?
As far as I understood from a series of papers, minimizing the T-count in Clifford+T circuits is essential for fault-tolerant ...
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1answer
110 views
Error while trying to execute the Quantum Circuits in IBMQ
I have been trying to execute the quantum circuit in the backend of the IBM 16 qubit Melbourne machine. I end up getting
...
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3answers
148 views
How are the IBM's and Google's Hadamard gates fabricated and operated?
There are thousands of articles, books and web sites describing the Hadamard Gate from a theoretical point of view.
But I haven't been able to find any photo about any real implementeation of a ...
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2answers
50 views
Unable to run a QRNG code
I am trying to run the above code on Vigo, Santiago and other backends. However, warning message as shown in the image apppears and no result is displayed even after hours of waiting. However, when I ...
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1answer
87 views
Simulating noise of googles quantum computers
Is there a way to simulate the noise of googles quantum computers using circ? In the same way that any of IBM's computers can be simulated using different backends?
...
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2answers
113 views
Is there a straightforward way to calculate the quantum volume for simple systems?
There are a few people who ask how to calculate IBM's "quantum volume", but it's not clear what the actual mathematical definition of this is. In the answers here, people just point to ...
3
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1answer
66 views
IBM Melbourne quantum computer performance and errors
What is the reason for high variation in measurement probability results of a simple 3/4 qubit measurement circuit on IBM Melbourne machine in comparison with the same circuit being run on IBM Vigo/...
0
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1answer
55 views
Why does job execution time vary significantly across different IBMQ Backends?
I have run a batch of a few thousand random 2-qubit QuantumCircuits on multiple different IBMQ Backends, and the execution times seem to significantly vary across ...
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1answer
1k views
Would IBM's “compiler” turn my identity circuit into nothing?
If I were to create a circuit with the following gate:
$$\tag{1}R_\phi = \begin{bmatrix} 1 & 0 \\ 0 & e^{i \phi} \end{bmatrix},$$
with $\phi$ specified to be equal to 0, then the gate that I ...
7
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3answers
114 views
What are the differences between the IBM machines?
I'm quite new to this field, and have started sending jobs to IBM's quantum computers. I have access to around 11 locations. I can see that these have different numbers of qubits within them, and then ...
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1answer
37 views
Dose Quantum threshold theorem apply to IBM Quantum Experience
According to Quantum threshold theorem, error rate can be arbitrarily low. But when I use IBM Quantum Experience to measure a simple $|+\rangle$, it gives result of $|1\rangle$ with probability of 52....
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5answers
492 views
Qiskit: Initializing $n$ qubits with binary values ($0$s and $1$s)
Is there a way in Qiskit to initialize $n$ qubits with binary values (0s and 1s)? For example, how can I initialize two qubits in the state $|11\rangle$? Here is a code snippet:
...
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2answers
56 views
How do you CNOT between qubits faraway from each other?
I'm just curious. Say I have 3 qubits on a straight line 0-1-2. How do you guys (on the IBMQ or Rigetti team for example, or anyone who actually works on quantum computer) entangle 0-2 if I, say, am ...
4
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0answers
96 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 ...
0
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2answers
327 views
IBMQ / Qiskit slack links are broken [closed]
It appears the Slack links to IBMQ slack pages are broken (The link is no longer active). This is case for links on both Qiskit and IBMQ support pages.
What is the best way to gain access to the Slack ...
2
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1answer
83 views
What extra functionality is available to an IBM Q Network member over a regular IBM Q Experience user
I've been trying to figure out the extra functionality available to IBM Q Network members that are not available to normal ...
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1answer
145 views
Quantum error correction on IBM devices?
I'm wondering if the gate errors on any of the IBM devices are low enough so that we could use some error correcting codes which do not require too many qubits? (such as 5- or 7-qubit codes). Even ...
