Pulse Sequences for NMR Quantum Computers: How to Manipulate Nuclear Spins While Freezing the Motion of Coupled Neighbours

Abstract

We show how to divide a coupled multi-spin system into a small subset of ``active'' spins that evolve under chemical shift or scalar coupling operators, and a larger subset of ``spectator'' spins which are returned to their initial states, as if their motion had been temporarily frozen. This allows us to implement basic one-qubit and two-qubit operations from which general operations on $N$-qubits can be constructed, suitable for quantum computation. The principles are illustrated by experiments on the three coupled protons of 2,3-dibromopropanoic acid, but the method is applicable to any spin-1/2 nuclei and to systems containing arbitrary numbers of coupled spins.

11 pages, 5 figs

References in corpus (4)

• Experimental realization of a quantum algorithm
• Implementation of a Quantum Search Algorithm on a Nuclear Magnetic Resonance Quantum Computer
• Nuclear magnetic resonance spectroscopy: An experimentally accessible paradigm for quantum computing
• Implementation of a Quantum Algorithm to Solve Deutsch's Problem on a Nuclear Magnetic Resonance Quantum Computer

Cited by in corpus (26)

• NMR Techniques for Quantum Control and Computation
• Observation of quantum oscillations between a Josephson phase qubit and a microscopic resonator using fast readout
• Recent progress and challenges in magnetic tunnel junctions with 2D materials for spintronic applications
• Quantum Computing with NMR
• Quantum simulation of a system with competing two- and three-body interactions
• Universal quantum computation and simulation using any entangling Hamiltonian and local unitaries
• Optimal simulation of two-qubit Hamiltonians using general local operations
• Simulation of a Heisenberg XY- chain and realization of a perfect state transfer algorithm using liquid nuclear magnetic resonance
• Efficient Refocussing of One Spin and Two Spin Interactions for NMR Quantum Computation
• Implementation of the refined Deutsch-Jozsa algorithn on a 3-bit NMR quantum computer
• NMR quantum computation with indirectly coupled gates
• Implementation of a quantum algorithm to solve Bernstein-Vazirani's parity problem without entanglement on an ensemble quantum computer
• Suppression of arbitrary internal coupling in a quantum register
• Realization of logically labeled effective pure states for bulk quantum computation
• Implementing unitary operators in quantum computation
• NMR Quantum Logic Gates for Homonuclear Spin Systems
• Nuclear Magnetic Resonance Implementation of a Quantum Clock Synchronization Algorithm
• Implementing universal multi-qubit quantum logic gates in three and four-spin systems at room temperature
• Speedup of quantum state transfer by three- qubit interactions: Implementation by nuclear magnetic resonance
• One- and two-dimensional N-qubit systems in capacitively coupled quantum dots
• Modularization of multi-qubit controlled phase gate and its NMR implementation
• Efficient experimental design of high-fidelity three-qubit quantum gates via genetic programming
• Controlling NMR spin systems for quantum computation
• "Spectral Implementation" for creating a labeled pseudo-pure state and the Bernstein-Vazirani's algorithm in a four-qubit nuclear magnetic resonance quantum processor
• Nuclear Spins as Quantum Testbeds: Singlet States, Quantum Correlations, and Delayed-choice Experiments
• Quantum Computing with Global One-and Two-Qubit Gates