All Questions
Tagged with error-correction qiskit
59
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How to implement fault tolerant cat state construction with qiskit?
I want to build a fault-tolerant error correction gadget in qiskit. As a part of that, I want to construct cat states (for the syndrome measurements) in a fault-tolerant way.
One way to do this, is to ...
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97
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Is this quantum circuit design more prone to noise?
I am designing a quantum circuit which uses one qubit as the control of many $\text{CSWAP}$ operations. And then, this qubit will be measured.
Will the result be more prone to noise since all the ...
- 121
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2
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94
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Error while plotting the resulting distribution
I am using this code, as a test of my qiskit, but I am having errors on using the simulator
Building the circuit
We begin by importing Qiskit.
from qiskit import *
...
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1
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20
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How to model the IBM quantum errors?
I'm conducting a study of the quantum channel errors, and a question has arisen: Is it possible to model the errors of an IBM quantum computer with Kraus operators?
3
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Does qiskit make any rounding errors or anything similar, or is it a perfect (but slow) simulation of a quantum computer?
I ran the following circuit to calculate the real part of the Bargmann Invariant of a system of quantum states. The invariant is defined as
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1
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159
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How to fix two flip-bit errors in a 3 qubit input
Aware of how a 1-bit flip can be fixed for 3-qubit input by having 2 Ancilla bits, encoding, and using the Toffoli gate to fix the error and decode. How can this idea be extended for a 2-bit flip (...
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239
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Get parameters of a CU gate for implementing an erroneous CX gate with fidelity = 0.81
Let's say the definition of an erroneous CNOT gate is given as - CNOT is a 2-qubit quantum gate when the control qubit is at state 0, applies identity operation on the target qubit, when the control ...
- 69
3
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134
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Quantum error correction circuit from stabilizer codes
I am trying to familiarize myself with QEC codes and their use in quantum communication. Right now, I am trying to implement some more widely known codes in Qiskit. My main problem is I cannot wrap my ...
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219
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Simulating a small distance surface code with individual qubit addressing
I want to simulate a small-distance surface code with either STIM or Qiskit. I want individual control over all the qubits (including the ancillas) to induce controlled errors in my circuit. I want to ...
- 239
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188
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How to see the effects of the depolarizing channel in qiskit?
I am playing around with adding noise to quantum circuit simulation using qiskit_aer.noise.NoiseModel(). My code creates a quantum circuit and simulates it with ...
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1
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134
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How to apply error-correction to the swap test circuit?
Swap test is a simple quantum circuit to measure the inner product of two quantum states [Wiki: swap test], it only contains three quantum gates. However, due to the error in the real quantum computer ...
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224
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How to implement Shor's 9-Qubit-Code in Qiskit?
I am new to qiskit and currently trying to implement Shor's 9-Qubit_Code. I am trying to orient my code on the example given in the official qiskit-tutorial and so far I have the following:
...
- 173
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177
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Are there qiskit or stim examples of how to decode a subsystem code
I can manage decoding a stabilizer code in qiskit and stim. I'd like to try a subsystem code next. For a stabilizer code, all stabilizers commute so simultaneous measurement of these produces ...
- 2,217
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1
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52
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How to best represent 5-Qbit codeword operator in Qiskit [duplicate]
We learned that in the 5-Qibit error correcting code, the logical zero state $ | \bar{0} \rangle $ is encoded in the form of $ \frac{1}{4} (\mathbb{1}+M_0)(\mathbb{1}+M_1)(\mathbb{1}+M_2)(\mathbb{1}+...
- 599
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1
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1
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194
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Measurement of readout errors for error mitigation algorithms
I am using an error mitigation algorithm that uses the readout errors p(0|1) and p(1|0) to correct the errors due to noise in my original circuit. I am trying to measure the readout errors in the same ...
- 199
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197
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Logical error rate for QECC using qiskit
I've been coding QECC with qiskit recently. As I'm not very skilled in programming I encountered a lot of questions.
Now I'm trying to generate the logical error rate against physical error rate graph ...
- 386
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182
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Qiskit, possible to manipulate mid-circuit measurement outcomes?
I'm currently coding up an error correction gadget using qiskit.
The one I'm doing now is 7-qubit Steane code with Steane's error correction gadget, in which the ancilla qubits are measured and then ...
- 386
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446
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Estimate of threshold values for 7-qubit Steane code with qiskit (or stim)
I have trouble recreating the graphs shown in this paper
https://arxiv.org/pdf/quant-ph/0508176.pdf
i.e. the quadratic trend of the logical error against physical single qubit error for [7,1,3] code
I ...
- 386
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78
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Why QECC amplitude damping error syndrome and qiskit simulation are different?
The [[3,0,2]] code, stabilizers are X1Z2I3,Z1X2Z3,I1Z2X3.
Use the circuit to decode and measure stabilizers:
As for amplitude damping error syndrome, use $\left[\begin{array}{cc}1 & 0 \\ 0 & ...
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How the real IBM quantum computers apply arbitrary Rz(θ) gate rotation? [closed]
I want to ask the following questions:
(1) The basis gate set of IBM quantum computers is { Id, Rz(θ),√X, X, CNOT, reset}. Somebody said that IBM didn’t really apply Rz(θ) gate on the machine. The ...
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269
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How to interface stim to a generic qiskit decoder?
I can generate encoder/decoder circuits for arbitrary QECC in qiskit. I tested a number of codes : $[[5,1,3]], [[7,1,3]],[[8,3,3]],\cdots$ and everything seems to work fine. The problem is that the ...
- 2,217
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416
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is cirq suitable for simulation of quantum error correction?
I experimented with stim and qiskit for QECC simulations. They both have limitations : for example stim has no support for non-clifford operations (qiskit does); qiskit has no support for multiple ...
- 2,217
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437
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how to go from matrix to tableau to circuit in qiskit or stim
I'm working with QECC using a non-python based platform. I'd like to move the results into python to do calculations that are better handled by packages like qiskit or stim. So the output of the non-...
- 2,217
3
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150
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How to set the meas_level and optimization_level in Quantum Azure IonQ provider?
I am performing a benchmark process using the Azure Quantum IonQ provider. I use Qiskit in the Azure platform, and I was trying to see how to control the transpiling and compiling process. It seems ...
- 284
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2
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155
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The statevector of three-qubit bit-flip encoding circuit for entangled state
I was trying to implement a three-qubit bit-flip code for shared entangled state. I was curious to analyze this mathematically, but the problem is I can't calculate the statevector after encoding. ...
- 374
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59
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How to set up a error detection and correction scheme on qiskit
Does, at the state of the art, Qiskit allows to do error detection and correction?
If yes, how can I do it?
- 1,998
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1
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242
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Information about the output of %qiskit_backend_overview
Does anyone know where can I find more information about the meaning of some parameters outputted by %qiskit_backend_overview ? I mostly refer to "Avg. T1/T2&...
0
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Is it possible for public users to run experiments using Qiskit's surface code?
I'm an undergrad who would like to run some experiments using the surface code. I've been able to use their quantum repetition code (https://qiskit.org/textbook/ch-quantum-hardware/error-correction-...
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247
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Why aren’t repetition codes used to encode qubits in superposition states?
I just finished reading the section of the qiskit textbook on quantum error correction using repetition codes(https://qiskit.org/textbook/ch-quantum-hardware/error-correction-repetition-code.html) and ...
- 103
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222
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Confusion about Mitiq folding for zero noise extrapolation
I'm reading the mitiq zero noise extrapolation documentation and I just can't make sense of how the scale_factor for folding work.
"The minimum scale factor is one (which corresponds to folding ...
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206
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Where does the "correction" in quantum error correction occur, specifically when using repetition codes?
I'm reading the part of the qiskit textbook that deals with this (https://qiskit.org/textbook/ch-quantum-hardware/error-correction-repetition-code.html) and so far it seems as though they're just ...
- 103
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191
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Qiskit noise model question (from textbook)
I'm reading the chapter Introduction to Quantum Error Correction using Repetition Codes and a code example demonstrates how to add depolarizing and pauli error. I have several questions.
Is it not ...
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84
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Can someone please explain how the syndrome bit still ends up being 0 in this quantum error correction circuit using repetition code?
I'm not too great at dealing with superpositions and applying the CNOT gate when superpositions are involved. Can you go through it in detail each gate using math/matrices etc. It's based on the ...
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Keep receiving Error - AttributeError: 'QuantumCircuit' object has no attribute 'save_statevector'
I am attempting to code a feed-forward simulation of a QECC in Qiskit. Qiskit (to my knowledge) does not directly support feed-forward simulation, so I attempted a work-around. I call the simulator ...
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2
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1
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137
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QPE Circuit test on Quantum Computer ('ibmq_16_melbourne')
After several atempts, I cannot mitigate the error when running the code on a NISQ, via the qiskit library (more specifically on the 'ibmq_16_melbourne').
I've already mapped the connected qubits and ...
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1
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361
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How to calculate the generators of a list of stabilizer?
Let's say we have a list of stabilizers: {'YZY*', 'XYY*', 'YZYZ', 'Z*Z*', '*XZ*', 'XZX*', 'ZX*Z', 'XZXZ', 'YYX*', 'Z*ZZ'}. Is there any existed formula or function (eg. in qiskit) that can calculate ...
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3
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252
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Quantum Error Correction implementation in Qiskit, OpenQASM or other languages based on Python
Where can we find example(s) of implementation code in a programming language of Quantum Error Correction, whether with the standard method of measurement or the automatic method without measurement (...
2
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0
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281
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How to implement Majority Vote
I am trying to boost the success probability of standard phase estimation by repeating the procedure enough times and taking a majority vote that will be encoded in a quantum register.
My problem is I ...
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1
answer
724
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Applying a projector to a qubit in a qiskit circuit
I'd like to be able to apply $|0 \rangle \langle 0|$ to project a qubit to the state $|0 \rangle$ in the middle of qiskit circuit (see, for example, the attached circuit).
I wonder if, in general, ...
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145
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Is there a way to entangle to a dirty qubit?
Let's say I do something to a qubit, and I want to entangle it to a 2nd one, like this:
...
- 584
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203
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Why and how is quantum noise predictable?
I have been learning about quantum error correction using the zero-noise extrapolation method from this paper and have been pleased with the results. This method takes advantage of the fact that the ...
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352
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Is it possible to implement c_if statement based on a measurement in a single specified classical bit in qiskit?
I'm trying to write a 1-bit teleportation error correction code and there is one part in it where I need to add a gate that's dependent on a measurement from earlier in the circuit. The measurement ...
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3
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882
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How to create the logical $|0_L\rangle$ state for the Steane's 7-qubit code?
I don't know how to prepare using Qiskit the following state in order to implement a Steane's 7-qubit code circuit (I omit the normalization factor):
\begin{align*} |0_L\rangle =&|0000000\rangle+|...
- 75
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1
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455
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How to do error mitigation on the ibmq_16_melbourne?
I'm trying to make a calibration matrix using CompleteMeasFitter as in here on IBMQ Melbourne, but I need to use all 15 qubits, which mean it has to run 32768 calibration circuit, far exceeding the 75 ...
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1
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269
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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 ...
- 1,981
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268
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Real-device error mitigation with qiskit
I'm trying to do error mitigation in IBM-Q quantum computers with qiskit. I followed the tutorial here. My thought was that in order to make sure that I'm correcting the qubits that I'm actually using ...
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2
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1
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153
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Specifying qubits to achieve measurement error mitigation on Qiskit
I'm learning how to do error mitigation on Qiskit as my experiment result differs from the simulated result. I read the tutorial here, but I have some questions about it. If I have understood it ...
- 99
2
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1
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484
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Different results between qasm_simulator and quantum computer: how to normalize for only few states
I recently started developing circuits with Qiskit. I made a 5 qubit circuit in which the fourth qubit at the end of execution must always have value 1:
When I do the simulation with qasm everything ...
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2
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1
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193
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Different QFT results when using Simulator or Quantum Machine
I'm performing QFT using the following code:
...
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