Ensemble Quantum Computing by Liquid-State NMR Spectroscopy
Abstract
The goals of this project were to use liquid-state nuclear magnetic resonance (NMR) as a testbed for developing general methods of solving computational problems on ensemble quantum computers, to study the fundamental physics and computer science behind such machines, and to learn how to make optimal use of the trade-offs that their unique capabilities permit us to make. During the three years of this project, we have: (1) developed a library of radio-frequency pulse sequences which allow a rich repertoire of unitary 'quantum logic gates' to be implemented by NMR; (2) designed general methods, based on magnetic field gradients, for preparing the 'pseudopure' states needed for quantum computing by liquid-state NMR; (3) invented procedures, based on gradients combined with molecular diffusion by which a wide variety of decoherent processes can be implemented using NMR; (4) used these procedures to perform the first demonstrations of quantum error correction as well as decoherence-free subspaces I systems; and (5) used the average Hamiltonian techniques developed many years ago by John Waugh at MIT to implement the first simulations of one quantum system by another, as originally proposed by Richard Feynman. Many of the techniques we have developed in the course of this work promise to be highly useful in other approaches to quantum computing, both by our group as well as many others.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 23, 2001
- Accession Number
- ADA390862
Entities
People
- David G. Cory
- Timothy E. Havel
Organizations
- Massachusetts Institute of Technology