Home > Quantum Error > Quantum Error Code Correction

# Quantum Error Code Correction

## Contents

When p < pt = 1/C, the fault-tolerance helps, decreasing the logical error rate. A more general class of codes (encompassing the former) are the stabilizer codes discovered by Daniel Gottesman ([1]), and by A. Since these two operations are completely separate, it can also correct Y errors as both a bit flip and a phase error. Their final state, if measured in the computational basis, contains the code syndrome. http://caribtechsxm.com/quantum-error/quantum-error-correction-code.php

I know that an arbitrary error can be expressed with the error base (phase flipe and bit flip), but I'm lacking the understanding of how does this assist me in deducing The sign flip code Quantum circuit of the phase flip code Flipped bits are the only kind of error in classical computer, but there is another possibility of an error with If U = i σ y {\displaystyle U=i\sigma _{y}} then both a bit flip error and a sign flip error occur. Itano, J. https://en.wikipedia.org/wiki/Quantum_error_correction

## Stabilizer Codes And Quantum Error Correction.

Therefore, given the ability to perform fault-tolerant Clifford group operations, fault-tolerant measurements, and to prepare the encoded ∣ψπ/8⟩ state, we have universal fault-tolerant quantum computation. Thus should be distinguished from the encoding operation which maps HlogK into Hn, determining the imbedding of C. Blatt, "Experimental Repetitive Quantum Error Correction," Science 332, 1059-1061 (2011), doi:10.1126/science.1203329 ^ M.

However, the theorem specifies the distance of the code by considering S ⊥  \ S. Freedman, Michael H.; Meyer, David A.; Luo, Feng: Z2-Systolic freedom and quantum codes. A transversal operation has the virtue that an error occurring on the 3rd qubit in a block, say, can only ever propagate to the 3rd qubit of other blocks of the 5-qubit Quantum Error Correction Nebendahl, D.

Larry Hardesty | MIT News Office May 26, 2015 Press Inquiries Share Press Contact Abby AbazoriusEmail: [email protected]: 617-253-2709MIT News Office Media Resources 1 images for download Access Media Media can only 5 Qubit Code That’s why it’s really desirable to reduce the number of qubits you have to measure at once.” Time embodied A quantum computation is a succession of states of quantum bits. This theorem seems to present an obstacle to formulating a theory of quantum error correction. http://news.mit.edu/2015/quantum-error-correction-0526 Calderbank, Peter Shor and Andrew Steane.

Fault-Tolerance Given a QECC, we can attempt to supplement it with protocols for performing fault-tolerant operations. Quantum Code 7 The bits are in some state; then they’re modified, so that they assume another state; then they’re modified again; and so on. Todd Brun, Igor Devetak, and Min-Hsiu Hsieh also constructed the entanglement-assisted stabilizer formalism as an extension of the standard stabilizer formalism that incorporates quantum entanglement shared between a sender and a Using the stabilizer formalism limits the available states but there is still a lot of interesting freedom.

1. Theorem 2 Let S be a stabilizer with n − k generators, and let S ⊥  = {E ∈ Pn s.t. [E, M] = 0 ∀M ∈ S}.
2. Suppose further that a noisy error corrupts the three-bit state so that one bit is equal to zero but the other two are equal to one.
3. Then the bit flip code from above can recover | ψ ⟩ {\displaystyle |\psi \rangle } by transforming into the Hadamard basis before and after transmission through E phase {\displaystyle E_{\text{phase}}}

## 5 Qubit Code

Andersen, "Quantum optical coherence can survive photon losses using a continuous-variable quantum erasure-correcting code," Nature Photonics 4, 700 (2010), doi:10.1038/nphoton.2010.168 Bibliography Daniel Lidar and Todd Brun, ed. (2013). "Quantum Error Correction". https://quantiki.org/wiki/quantum-error-correction-and-fault-tolerance-0 Category:Introductory Tutorials Category:Quantum Error Correction Category:Handbook of Quantum InformationLast modified:Monday, October 26, 2015 - 17:56 current community blog chat Theoretical Computer Science Theoretical Computer Science Meta your communities Sign up or Stabilizer Codes And Quantum Error Correction. The simplest method, due to Shor, is very general but also requires the most overhead and is frequently the most susceptible to noise. Steane Code If the three bit flip group (1,2,3), (4,5,6), and (7,8,9) are considered as three inputs, then the Shor code circuit can be reduced as a sign flip code.

Peter Shor first discovered this method of formulating a quantum error correcting code by storing the information of one qubit onto a highly entangled state of nine qubits. navigate to this website Cambridge University Press. ^ W.Shor, Peter (1995). "Scheme for reducing decoherence in quantum computer memory". Langer, R. Knill, R. Quantum Error Correction Book

Here R {\displaystyle {\mathcal {R}}} is known as the correction operation. Zurek, T. But, Harrow says, “Almost all of the sparse schemes started out with not very many logical qubits, and then people figured out how to get a lot more. More about the author Then we interact the ancilla with the encoded data qubits using gates from our stock of transversal gates and perform a fault-tolerant measurement.

A 71, 052332 (2005), doi:10.1103/PhysRevA.71.052332 ^ J. Fault-tolerant Quantum Computation Then if only one bit is flipped, we might get the state 011, and we can deduce that the original state was 111. What does "they are facing their chest and shoulder" mean in this paragraph?

## The first demonstration was with NMR qubits.[4] Subsequently, demonstrations have been made with linear optics,[5] trapped ions,[6][7] and superconducting (transmon) qubits.[8] Other error correcting codes have also been implemented, such as

Why do units (from physics) behave like numbers? Schoelkopf, "Realization of Three-Qubit Quantum Error Correction with Superconducting Circuits," Nature 482, 382-385 (2012), doi:10.1038/nature10786, arXiv:1109.4948 ^ M. Through the transmission in a channel the relative sign between | 0 ⟩ {\displaystyle |0\rangle } and | 1 ⟩ {\displaystyle |1\rangle } can become inverted. Bit Flip Memory Error How does break enchantment work on stone shaped wall?

If one of the qubits turns out to disagree with the other two, it can be reset to their value. A generalisation of this concept are the CSS codes, named for their inventors: A. These include EPR and GHZ states. click site Jost, E.

And for reasonably sized quantum computers, that fraction can be arbitrarily large — although the larger it is, the more qubits the computer requires. “There were many, many different proposals, all The computational complexity of the encoder is frequently a great deal lower than that of the decoder. The 1st, 4th and 7th qubits are for the sign flip code, while the three group of qubits (1,2,3), (4,5,6), and (7,8,9) are designed for the bit flip code. According to the quantum Hamming bound, encoding a single logical qubit and providing for arbitrary error correction in a single qubit requires a minimum of 5 physical qubits.

A transversal operation is one in which the ith qubit in each block of a QECC interacts only with the ith qubit of other blocks of the code or of special A non-degenerate code is one for which different elements of the set of correctable errors produce linearly independent results when applied to elements of the code. Sun, L. Chwalla, M.

The Pauli group Pk, however, can be performed transversally on any stabilizer code. However, by taking appropriate products, we get an infinite set of gates, one that is dense in the unitary group U(2n), allowing universal quantum computation. The first step of the three qubit bit flip code is to entangle the qubit with two other qubits using two CNOT gates with input | 0 ⟩ {\displaystyle |0\rangle } We need to add some additional gate outside the Clifford group to allow universal quantum computation; a single gate will suffice, such as the single-qubit π/8 phase rotation diag(1, exp(iπ/4)).

Reed, L. For a quantum code, we need a bit more. It is assumed that measurements and classical computations can be performed quickly and reliably, and that quantum gates can be performed between arbitrary pairs of qubits in the computer, irrespective of Britton, W.

D. If U = i σ y {\displaystyle U=i\sigma _{y}} then both a bit flip error and a sign flip error occur. Note that the square brackets specify that the code is a stabilizer code, and that the middle term k refers to the number of encoded qubits, and not the dimension 2k Through the transmission in a channel the relative sign between | 0 ⟩ {\displaystyle |0\rangle } and | 1 ⟩ {\displaystyle |1\rangle } can become inverted.