Microscopic analogs of the Greenberger-Horne-Zeilinger experiment on an NMR quantum computer
Abstract
A scheme is proposed to implement microscopic analogs of the Greenberger-Horne-Zeilinger experiment, as described by Lloyd, on a nuclear magnetic resonance (NMR) quantum computer. This scheme includes how to prepare the effective pure spin state \|0000> (a state with all the spins pointing along the direction of the magnetic field) from a state at thermal equilibrium, how to transform it into states of the form, e.g., (\|000>-\|111>)\|0> (which comprises the first three spins in an entangled state and the fourth register-spin), and how to measure the eigenvalue of the operator product like σ1xσ2yσ3y for such three-spin entangled states, where σi is the Pauli matrix for the ith spin, and store the result on the fourth spin. Also proposed is a general method to implement the controlled-not gate, an essential gate for any quantum algorithm, on n-qubit NMR quantum computers with n>=4.
- Publication:
-
Physical Review A
- Pub Date:
- September 1999
- DOI:
- 10.1103/PhysRevA.60.1906
- Bibcode:
- 1999PhRvA..60.1906S
- Keywords:
-
- 03.67.Lx;
- 03.65.Bz;
- 76.60.-k;
- Quantum computation;
- Nuclear magnetic resonance and relaxation