All Questions
Tagged with ibm-q-experience ibm-q-experience or
105 questions with no upvoted or accepted answers
6
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Quantum State Tomography Implementation in IBMQ
I am working to understand quantum state tomography, specifically using the algorithm presented in PRL 108, 070502. This paper is referenced in IBMQ implementations of QST, both in old deprecated ...
6
votes
0
answers
141
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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 ...
- 101
5
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0
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271
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How to get the compiled circuits and measurements from a Qiskit Runtime job
I have not been able to find any way to retrieve the compiled circuits and the measurement counts used for a Qiskit Runtime job. This page describes the various error suppression mechanisms available. ...
- 726
5
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113
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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 ...
- 565
5
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160
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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 ...
- 83
4
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0
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361
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Implementing Shor's algorithm on IBM Quantum Composer
I'm trying to recreate
from this paper in the IBM Quantum Composer. However, this circuit isn't enough understandable for me to do so.
I have tried to recreate the above circuit in the composer as ...
- 157
4
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0
answers
86
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Incorrect probabilities in IBMQ Mid-circuit measurements
I calculated the probabilities for two measurements using mid-circuit measurements feature in IBMQ by following circuit:
...
4
votes
0
answers
72
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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. ...
- 641
4
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69
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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 ...
4
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0
answers
161
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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:
...
- 2,408
4
votes
0
answers
82
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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 ...
- 51
4
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0
answers
146
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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 ...
4
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335
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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 ...
- 41
4
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0
answers
563
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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 ...
- 101
4
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0
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480
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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 ...
- 313
3
votes
1
answer
244
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How to re-execute failed jobs in qiskit?
When executing a batch of circuits using the IBMQJobManager and attempting to combine all the results of all jobs with combine_results I get the ...
- 431
3
votes
1
answer
382
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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 ...
- 57
3
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46
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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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3
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183
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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 ...
- 131
3
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answers
649
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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,...
- 313
3
votes
0
answers
672
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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 ...
- 333
2
votes
0
answers
74
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Understanding sources of error in 4-bit Grover's search on IBM QC
This question is similar to some others I've come across, related to why a 4-qubit implementation of Grover's search yields such poor results when run on the IBM QC compared to the 3-qubit case (...
- 121
2
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0
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42
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Controlled Ry gate on IBM and IonQ basis gates
As far as I know the basis gates for IBM and IonQ are:
IBM: ['cx', 'id', 'rz', 'x', 'sx']
IonQ: ['rx', 'ry', 'rz', 'rxx', 'id']
I used qiskit.transpile to see check how Controlled Ry gate can be ...
- 21
2
votes
0
answers
82
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Quantum Annealing on IBMQ using Qiskit-Pulse
Qiskit-Pulse is the analog level control SDK of IBMQ hardware. Is it possible to implement an adiabatic annealing protocol/algorithm on IBMQ hardware using Qiskit-Pulse?
Not asking about QAOA, which I ...
2
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0
answers
59
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A path towards building quantum Computing graduation project for undergraduates
I need help. I'm a computer science student with a Data science major. I have a final graduation project this year. With that, I want to create a project in the Quantum computing field. I'm already ...
2
votes
0
answers
235
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Calculating the Inner Product using Quantum Phase Estimation
I'm following the method laid out in https://arxiv.org/abs/2011.03429 (Page 23 Equations 13-23) to calculate the inner product of two amplitude embedded vectors using Quantum Phase Estimation. I'm ...
- 63
2
votes
0
answers
229
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How to formulate QUBO as summation quadratic and linear parts of K-graph coloring problem?
While trying to understand the graph coloring problem with VQE using the QUBO Formulation mentioned section "5.2 Graph Coloring". Mentioned article prepared the QUBO directly in to matrix ...
- 31
2
votes
0
answers
148
views
Eigenvalues and energy levels of 1D Heisenberg model using real Quantum Computers?
The 1D Quantum Heisenberg model is
$$H_\textrm{Heisenberg} = -~J \sum_{\langle i\ j\rangle} \hat{S}_{i} \cdot \hat{S}_{j}$$
where each spin is an operator.
For simple cases, for example, a system with ...
- 375
2
votes
0
answers
317
views
How can I add custom pulse gate to the Qiskit circuit?
I tried to make my pulse and get the pulse into the circuit. But it seems not working properly.
The code and the result are below.
Just change the 'x' to the 'h' (hadamard) with the same piecewise ...
- 21
2
votes
0
answers
66
views
Does dedicated mode provide better results than fairshare in mid-circuit measurement?
I'm using a research account and I have a question about running circuits with (dedicated/priority mode) and without reservation (fair-share mode). From the documentation of dedicated mode,
This (The ...
- 2,408
2
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0
answers
39
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Recover qubits used in an actual computation
How do I recover from a certain job_id in the IBM backends which qubits where used?
I would be interested to know if for instance, in a batch of say 50 jobs, 25 of ...
- 641
2
votes
0
answers
450
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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:...
- 21
2
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0
answers
111
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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 ...
2
votes
0
answers
145
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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 ...
- 76
2
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0
answers
140
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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. ...
- 14.9k
2
votes
1
answer
162
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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2
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0
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44
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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 ...
2
votes
0
answers
53
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 ...
- 105
2
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0
answers
227
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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:
<...
- 116
2
votes
0
answers
199
views
Number of Shots always 1024/or nothing (IBM q experience)
I have been running some simple "Hello Quantum World" code and every time I try to run it on 4096 shots or 8192 shots, the results always show as if I ran the code on 1024 shots (or in the most recent ...
- 21
2
votes
0
answers
1k
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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.
...
- 191
1
vote
0
answers
17
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How to get historical calibration data for mthree (M3) from IBM Quantum devices?
I'm using mthree in Batch mode. A batch needs to be queued before it can be executed. The time when a batch was executed can be obtained from the IBM Quantum Platform site, so I would like to obtain ...
- 11
1
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74
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Performance of quantum annealing systems vs gate based ones
Quantum annealers like D-Wave can be used to solve Quadratic Unconstrained Binary Optimization (QUBO) which is a NP Hard problem (see here) while gate based quantum computers, like the ones created by ...
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1
vote
0
answers
24
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Are reset gates allowed on IBM quantum computers?
My circuit involves many "reset" gates. After running on the IBM real backend, the experiment status says "Failed" with error message that says:
Failed - Unknown operation type ...
- 231
1
vote
0
answers
60
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qiskit transpile taking forever to run while CPU usage near zero
I am using the following code to use IBM's quantum computer. My understanding is that it is required before circuits are passed to the real quantum computers as certain operations and instructions ...
- 231
1
vote
0
answers
68
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Low Fidelity In IBM Quantum Computers
I am just trying to calculate the highest fidelity of preparing GHZ states on IBM quantum computers and I run my circuit on qubits with the lowest readout error. However, I just obtain fidelity of the ...
- 121
1
vote
0
answers
63
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Interleaved Randomized Benchmarking experiment with custom PassManager
I have a custom PassManager, which calibrates a few gates in the circuit in the transpiler pass. I want to conduct an Interleaved Randomized Benchmarking experiment ...
- 135
1
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0
answers
42
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How to represent the gates and the quibit states in the 'Hello Quantum' iOS game in IBM Quantum Learning graphical simulator
The Hello Quantum ios game developed by IBM has the X, Z, H and CZ gates manipulating a 2 qubit array (im not sure if array is the right word?).
I want to know how I can represent the qubit states in ...
- 51
1
vote
0
answers
34
views
ZNE for mitigating errors in probability distribution results
Can ZNE be applied to mitigate errors for getting the probability distribution in the computational basis rather than mitigating errors for calculation of expectation values?
- 135
1
vote
0
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80
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In qubit phase tracking, does the phase $\delta$ have to be synchronized to the Larmor precession?
In many textbooks (e.g. LaPierre 2021 or Byrd 2022), when dealing with the physical implementation of quantum gates in spin qubits, Larmor precession is usually introduced first as a way to rotate the ...
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