CSASM Seminar: Experimental Quantum Error Correction

Laurier Seminar Series in Computational Science and Applied & Statistical Modelling (CSASM)

Speaker: Raymond Laflamme, Canada Research Chair in Quantum Information Executive Director, Institute for Quantum Computing Director, CIFAR QIP program, University of Waterloo

Title: Experimental Quantum Error Correction

Thursday, April 29, 2010 4:00 p.m. Room: N1044. The talk will be recorded and available on our training wiki once edits are complete.

printable poster

Abstract: Information processing devices are pervasive in our society; from the 5dollar watches to multi-billions satellite network. These devices have allowed the information revolution which is developing around us. It has transformed not only the way we communicate or entertain ourselves but also the way we do science and even the way we think. All this information is manipulated using the classical approximation to the laws of physics, but we know that there is a better approximation: the quantum mechanical laws. Using quantum mechanics for information processing turns out not to be an impediment but leads to a dramatic advantage for manipulating information. The Achilles heel of quantum information is however its fragility. While we are learning how to build quantum processor, we must learn to make them robust: quantum error correction aims to do this. Quantum error correction and its fault tolerant extension lead to the accuracy threshold theorem which says that despite some noise, at a level below the threshold, it is still possible to quantum compute efficiently. Underlying this theorem is an assumption on noise models that hopefully are physically reasonable. This talk will give a method to learn about the noise model for quantum information processing device having in mind quantum error correction. Standard methods for measuring the noise are based on quantum process tomography and require an exponentially large number of experiments. I will describe protocols that will determine efficiently the probability of k errors independently of which qubit is affected and which type of error it is for memory based on the ideas described in Emerson et al. (Science 317, 1893, 2007). I will also discuss characterization of errors for one and two bits gates based on the work of Knill ( arXiv:0707.0963). I will also describe work on benchmarking of quantum gates whose goals is to assess the performance of quantum information processors ( arXiv:0808.3973). I will give an overview of experimental implementation on these ideas using NMR in both the liquid and solid-state.