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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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
27 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:
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36 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
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2answers
53 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 ...
4
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0answers
38 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
36 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
71 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
41 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
82 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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4
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2answers
75 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
49 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/...
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1answer
36 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
102 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
34 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
171 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
52 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 ...
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0answers
78 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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2answers
197 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 ...
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1answer
77 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
89 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 ...
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1answer
141 views
How can I install the 'ibmq_qasm_simulator' backend?
I'm having trouble running the following cell:
The system told me "The 'ibmq_qasm_simulator' backend is not installed in your system." I'm so confused. Is there a way I can install this backend in my ...
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1answer
32 views
Conversion of python code on Machine learning to realise on quantum processor
I need to realise a Python code program on Qiskit. It works on fuzzy logic. How should I realise the same using quantum processors using Qiskit? Is there any support on realising Python code for Fuzzy ...
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1answer
44 views
Graphing T1 using Qiskit
I am trying IBM's code for graphing T1 and I keep getting the following error:
...
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1answer
47 views
How can I find the most suitable IBMQ provider for my location? [duplicate]
I have been trying to run my code on IBM's quantum computers, so I used the following commands to associate a quantum computer to the component qcomp:
...
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3answers
74 views
Trying to get a provider from IBMQ but get 'No provider matches the criteria.'
I have created a circuit and then run the following:
provider = IBMQ.get_provider('ibm-q')
And this is what I get:
...
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1answer
247 views
Error while running the circuit on a real device on IBMQ
I have been trying to run a circuit on ibmq_16_melbourne. But the result shows ERROR_RUNNING_JOB. The run status says:
...
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3answers
178 views
Error while running Quantum Teleportation Algorithm on real device using qiskit on IBM-Q
I am trying to implement Quantum Teleportation Algorithm on an actual device, I am using IBM-Q Jupyter notebook for the same purpose.
The code is as follows:
...
2
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1answer
330 views
How many Qubits does the qiskit implementation of Shor's Algorithm need to factor N=15?
I know there is a documentation for qiskit.aqua.algorithms.Shor that explains that they used this reference for implementing the actual circuit. It says that the number of qubit needed is 2n+3. So to ...
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1answer
63 views
How to deal with the relative phase from the evaluation of the not interacting qubit?
Every qubit is a realization of some two-level quantum system with $\left| 0 \right\rangle$ and $\left| 1 \right\rangle$ states. These states have their energies $E_0$ and $E_1$ respectively. By ...
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2answers
407 views
'IBMQFactory' object has no attribute 'load_accounts'
I am following this qiskit workshop from https://colab.research.google.com/github/mtreinish/qiskit-workshop/blob/master/Workshop.ipynb . After adding my API key I had encountered the error ...
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0answers
80 views
Grover's algorithm for 3SAT problem gives erroneous results
I'm writing a code in python with qiskit that implements Grover's algorithm to solve the 3-SAT problem, but when I run it it doesn't give the correct annswer. I've checked the circuit with the ...
3
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2answers
124 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
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1answer
264 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 ...
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1answer
259 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 ...
6
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1answer
296 views
Why does Google's quantum processor outperform IBM's?
I understand that both have 53 qubit devices, yet it is Google that has demonstrated quantum supremacy (although IBM refutes this!). I'm not sure if this is true but it seems like IBM cannot replicate ...
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3answers
440 views
Why do the IBM and Google processors both have 53 qubits?
As I understand from this IBM post both the IBM and Google teams have independently built 53-qubit processors. What is the significance of the number 53? It is purely coincidental, or is there a ...
2
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1answer
80 views
Can we simulate quantum many-body systems with IBMQ Experience?
Consider physical systems such as electrons in metals, or Bose-Einstein condensates, or any crystal, which are realised in the real three-dimensional space.
If we want to simulate these systems on a ...
0
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1answer
303 views
Problem with initial_layout on Qiskit/IBMQ: 'Not enough qubits in CouplingGraph'
I am trying to run an execution on IBMQx2 where I can specify the physical qubits to which I apply gates. The execution without the initial_layout runs fine, but ...
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0answers
233 views
Comparing CPU to QPU In terms of processing power
The current processors are limited by the speed of the electrons but quantum processors take advantage of the properties of subatomic particles. But the question is how to compare the processing power ...
2
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1answer
278 views
IBM Slack links broken
Does anyone know where I can find working Slack invite links to any of IBM's Slack pages? The Slack links on this support page are all broken. Thank you.
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0answers
89 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 ...
3
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1answer
515 views
IBM's quantum computing capabilities — entangled 18-qubit GHZ states and high coherence times
Here's a blog post that corresponds with what IBM presented at the 2019 March Meeting.
In this post, they claim they've measured qubit T1 relaxation times above 500 microseconds, and claim that they'...
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0answers
44 views
What is the difference in computational power between qubit and bit (transistor)? [duplicate]
If I use for example 5-qubit IBM-Q quantum computer and we accept the law of quantum parallelism ($n$ qubit = $2^n$ ordinary bits), so does it mean that computational power of this computer is equal ...
2
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2answers
267 views
Experiment runtime on IBMQ
I have been trying to get the runtime of my experiment on IBM's quantum computer. I am using the classic stuff, i.e
...
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1answer
118 views
Graphing the decoherence of qubits being used to perform an algorithm
How would I be able to graph the decoherence of qubits being used to perform an algorithm? I'm working with the IBMQ Qiskit framework and I'm trying to write a program that allows me to find the ...
2
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1answer
74 views
How many physical qubits are used when I run a program on a IBM Q computer?
How do I find out how many physical-qubits I'm using when I run my program in an IBM Q backend quantum computing system?
6
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2answers
632 views
What is maximum circuit depth and size IBM Q5 and Q16 could handle?
I'm trying to implement a couple of algorithms on ibmq_16_melbourne, so I need to know if this device is able to handle with depth and size of my current circuit or ...
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1answer
180 views
Current limits on Grover search space
I was wondering why till date Grover search has been implemented only till 3 qubits (corresponding to size of database = 8). Refer this paper
The reason why I ask is that we have much larger sized ...
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0answers
50 views
Can “experimental data from a quantum computer” be used to test separability probability conjectures?
An article entitled "Experimental data from a quantum computer verifies the generalize Pauli exclusion principle" by Scott E. Smart, David I. Schuster, and David A. Mazziotti has just appeared
In the ...
