There are many more algorithms and benchmarks that can be usefully explored using the liquid-state NMR platform. We hope to soon have a molecule with ten or more useful spins and good properties for QIP. Initially this molecule can be used to extend and verify the behavior of existing scalable benchmarks. Later, experiments testing basic ideas in physics simulation or more sophisticated noise-control methods are likely.
Liquid-state NMR QIP is one of many ways in which NMR can be used for quantum information. One of the promising proposals for quantum computation is based on phosphorus embedded in silicon [43] and involves controlling phosphorus nuclear spins using NMR methods. In this proposal, couplings and frequencies are controlled with locally applied voltages. RF pulses can be used to implement universal control. It is also possible to scale up NMR QIP without leaving the basic paradigms of liquid-state NMR while adding such features as high polarization, the ability to dynamically reset qubits (required for scalability) and much faster two-qubit gates. One proposal for achieving this goal is to use dilute molecules in a solid state matrix instead of molecules in liquid [44]. This approach may lead to pure-state quantum computation for significantly more than ten qubits.
NMR QIP has been a useful tool for furthering our understanding of the experimental challenges of quantum computation. We believe that NMR QIP will continue to shed light on important issues in physically realizing quantum information.
Acknowledgements: We thank Nikki Cooper and Ileana Buican for their extensive encouragement and editorial help.
Addresses:
| R. Laflamme: | University of Waterloo and Perimeter Institute | laflamme@iqc.ca |
| E. Knill: | Los Alamos National Laboratory | knill@lanl.gov |
| D. Cory: | MIT | dcory@mit.edu |
| E. M. Fortunato: | '' | evanmf@mit.edu |
| T. Havel: | '' | tfhavel@mit.edu |
| C. Miquel: | FCEN, Univ. Buenos Aires | miquel@df.uba.ar |
| R. Martinez: | Los Alamos National Laboratory | rudy@lanl.gov |
| C. Negrevergne: | '' | cjn@lanl.gov |
| G. Ortiz: | '' | g_ortiz@lanl.gov |
| M. A. Pravia: | MIT | praviam@mit.edu |
| Y. Sharf: | '' | ysharf@mit.edu |
| S. Sinha: | '' | suddha@mit.edu |
| R. Somma: | Los Alamos National Laboratory | somma@lanl.gov |
| L. Viola: | '' | lviola@lanl.gov |