arXiv subjects

W. C. Holton

Publications and source records attributed to W. C. Holton.

5 recordsLinked to original sources

arXiv2001

Orchestrating an NMR quantum computation: the N=3 Deutsch-Jozsa algorithm

A detailed description of the development of a three qubit NMR realization of the Deutsch-Jozsa algorithm [Collins et.al., Phys. Rev. A 62, 022304 (2000)] is provided. The theoretical and experimental techniques used for the reduction of the algorithm's evolution steps into a sequence of NMR pulses are discussed at length. This includes the description of general pulse sequence compilation techniques, various schemes for indirectly coupled gate realizations, experimental pulse parameterization techniques and bookkeeping methods for pulse phases.

quant-ph↗

arXiv2000

A scalable solid-state quantum computer based on quantum dot pillar structures

We investigate an optically driven quantum computer based on electric dipole transitions within coupled single-electron quantum dots. Our quantum register consists of a freestanding n-type pillar containing a series of pair wise coupled asymmetric quantum dots, each with a slightly different energy structure, and with grounding leads at the top and bottom of the pillar. Asymmetric quantum wells confine electrons along the pillar axis and a negatively biased gate wrapped around the center of the pillar allows for electrostatic confinement in the radial direction. We self-consistently solve coupled Schrodinger and Poisson equations and develop a design for a three-qubit quantum register. Our results indicate that a single gate electrode can be used to localize a single electron in each of the quantum dots. Adjacent dots are strongly coupled by electric dipole-dipole interactions arising from the dot asymmetry, thus enabling rapid computation rates. The dots are tailored to minimize dephasing due to spontaneous emission and phonon scattering and to maximize the number of computation cycles. The design is scalable to a large number of qubits.

cond-mat↗

arXiv1999

NMR quantum computation with indirectly coupled gates

An NMR realization of a two-qubit quantum gate which processes quantum information indirectly via couplings to a spectator qubit is presented in the context of the Deutsch-Jozsa algorithm. This enables a successful comprehensive NMR implementation of the Deutsch-Jozsa algorithm for functions with three argument bits and demonstrates a technique essential for multi-qubit quantum computation.

quant-ph↗

arXiv1999

An optically driven quantum dot quantum computer

We propose a quantum computer structure based on coupled asymmetric single-electron quantum dots. Adjacent dots are strongly coupled by means of electric dipole-dipole interactions enabling rapid computation rates. Further, the asymmetric structures can be tailored for a long coherence time. The result maximizes the number of computation cycles prior to loss of coherence.

quant-ph↗

arXiv1998

Deutsch-Jozsa algorithm as a test of quantum computation

A redundancy in the existing Deutsch-Jozsa quantum algorithm is removed and a refined algorithm, which reduces the size of the register and simplifies the function evaluation, is proposed. The refined version allows a simpler analysis of the use of entanglement between the qubits in the algorithm and provides criteria for deciding when the Deutsch-Jozsa algorithm constitutes a meaningful test of quantum computation.

quant-ph↗