Demonstrating Quantum Error Correction at the Break Even Point

by Ofek Nissim

at Condensed Matter Theory Seminar

Wed, 30 Dec 2015, 13:30
Physics building (#54) room 207

Abstract

Quantum error correction QEC is necessary to protect fragile quantum states from the detrimental effects of unwanted couplings to a system s environment Typical approaches to realizing a QEC scheme involve redundantly encoding a quantum bit qubit into a larger space of quantum states that have symmetry properties or parities that allow one to measure observable error syndromes without corrupting the encoded information Traditional approaches to QEC such as the Steane or surface code involve logical encodings that employ large numbers of physical qubits and error syndrome measurements enhancing decay rates significantly and requiring considerable hardware overhead to realize A hardware efficient proposal which we term the cat code sheds much of this complexity by encoding a qubit in superpositions of cat states in a long lived superconducting resonator which has one dominant error syndrome: single photon loss As these cat states are eigenstates of photon numb er parity the loss of a single photon changes the parity without corrupting the encoded information Here in a superconducting cQED architecture we demonstrate that we can track these errors in real time with repeated single shot parity measurements and map their occurrence onto applications of a known unitary rotation of an arbitrary encoded state in the logical space With these capabilities we could realize a full QEC system that can store a quantum bit of information for longer time than any of its constituents

Created on 25-12-2015 by Bar Lev, Yevgeny (ybarlev)
Updaded on 25-12-2015 by Bar Lev, Yevgeny (ybarlev)