Related Experiment Video
Updated: Feb 13, 2026

Gradient Echo Quantum Memory in Warm Atomic Vapor
Published on: November 11, 2013
Defects in Quantum Computers
Bartłomiej Gardas1,2,3, Jacek Dziarmaga4, Wojciech H Zurek1
1Theoretical Division, LANL, Los Alamos, New Mexico, 87545, USA.
Abstract:
The shift of interest from general purpose quantum computers to adiabatic quantum computing or quantum annealing calls for a broadly applicable and easy to implement test to assess how quantum or adiabatic is a specific hardware. Here we propose such a test based on an exactly solvable many body system-the quantum Ising chain in transverse field-and implement it on the D-Wave machine. An ideal adiabatic quench of the quantum Ising chain should lead to an ordered broken symmetry ground state with all spins aligned in the same direction. An actual quench can be imperfect due to decoherence, noise, flaws in the implemented Hamiltonian, or simply too fast to be adiabatic. Imperfections result in topological defects: Spins change orientation, kinks punctuating ordered sections of the chain. The number of such defects quantifies the extent by which the quantum computer misses the ground state, and is, therefore, imperfect.
Related Concept Videos
Quantum Numbers
The Quantum-Mechanical Model of an Atom
Lumber Defects
Shakes are minor fractures that run along or across the wood's annual rings, while wane is...
Computed Tomography
The technique was invented in the 1970s and is based on the principle that as X-rays pass through the body, they are absorbed or reflected at different levels. In the technique, a patient lies on a motorized platform while a computerized axial tomography (CAT) scanner rotates...
Design Example: Traverse Angle Computations
Area Computation by the Alternative Coordinate Method

