# Repeat-until-success quantum computing using stationary and flying qubits

## Abstract

We introduce an architecture for robust and scalable quantum computation using both stationary qubits (e.g., single photon sources made out of trapped atoms, molecules, ions, quantum dots, or defect centers in solids) and flying qubits (e.g., photons). Our scheme solves some of the most pressing problems in existing nonhybrid proposals, which include the difficulty of scaling conventional stationary qubit approaches, and the lack of practical means for storing single photons in linear optics setups. We combine elements of two previous proposals for distributed quantum computing, namely the efficient photon-loss tolerant build up of cluster states by Barrett and Kok [Phys. Rev. A 71, 060310(R) (2005)] with the idea of repeat-until-success (RUS) quantum computing by Lim et al. [Phys. Rev. Lett. 95, 030505 (2005)]. This idea can be used to perform eventually deterministic two qubit logic gates on spatially separated stationary qubits via photon pair measurements. Under nonideal conditions, where photon loss is a possibility, the resulting gates can still be used to build graph states for one-way quantum computing. In this paper, we describe the RUS method, present possible experimental realizations, and analyze the generation of graph states.

- Authors:

- Blackett Laboratory, Imperial College London, Prince Consort Road, London SW7 2BZ (United Kingdom)
- Hewlett-Packard Laboratories, Filton Road, Stoke Gifford, Bristol BS34 8QZ (United Kingdom)
- National Institute of Education, Nanyang Technological University, Singapore 63 9798 (Singapore)
- (Singapore)

- Publication Date:

- OSTI Identifier:
- 20786649

- Resource Type:
- Journal Article

- Resource Relation:
- Journal Name: Physical Review. A; Journal Volume: 73; Journal Issue: 1; Other Information: DOI: 10.1103/PhysRevA.73.012304; (c) 2006 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)

- Country of Publication:
- United States

- Language:
- English

- Subject:
- 74 ATOMIC AND MOLECULAR PHYSICS; ATOMS; GRAPH THEORY; IONS; MOLECULES; OPTICS; PHOTONS; QUANTUM COMPUTERS; QUANTUM DOTS; QUBITS; SOLIDS; TRAPPING

### Citation Formats

```
Lim, Yuan Liang, Beige, Almut, Barrett, Sean D., Kok, Pieter, Kwek, Leong Chuan, and Department of Physics, National University of Singapore, Singapore 11 7542.
```*Repeat-until-success quantum computing using stationary and flying qubits*. United States: N. p., 2006.
Web. doi:10.1103/PHYSREVA.73.0.

```
Lim, Yuan Liang, Beige, Almut, Barrett, Sean D., Kok, Pieter, Kwek, Leong Chuan, & Department of Physics, National University of Singapore, Singapore 11 7542.
```*Repeat-until-success quantum computing using stationary and flying qubits*. United States. doi:10.1103/PHYSREVA.73.0.

```
Lim, Yuan Liang, Beige, Almut, Barrett, Sean D., Kok, Pieter, Kwek, Leong Chuan, and Department of Physics, National University of Singapore, Singapore 11 7542. Sun .
"Repeat-until-success quantum computing using stationary and flying qubits". United States.
doi:10.1103/PHYSREVA.73.0.
```

```
@article{osti_20786649,
```

title = {Repeat-until-success quantum computing using stationary and flying qubits},

author = {Lim, Yuan Liang and Beige, Almut and Barrett, Sean D. and Kok, Pieter and Kwek, Leong Chuan and Department of Physics, National University of Singapore, Singapore 11 7542},

abstractNote = {We introduce an architecture for robust and scalable quantum computation using both stationary qubits (e.g., single photon sources made out of trapped atoms, molecules, ions, quantum dots, or defect centers in solids) and flying qubits (e.g., photons). Our scheme solves some of the most pressing problems in existing nonhybrid proposals, which include the difficulty of scaling conventional stationary qubit approaches, and the lack of practical means for storing single photons in linear optics setups. We combine elements of two previous proposals for distributed quantum computing, namely the efficient photon-loss tolerant build up of cluster states by Barrett and Kok [Phys. Rev. A 71, 060310(R) (2005)] with the idea of repeat-until-success (RUS) quantum computing by Lim et al. [Phys. Rev. Lett. 95, 030505 (2005)]. This idea can be used to perform eventually deterministic two qubit logic gates on spatially separated stationary qubits via photon pair measurements. Under nonideal conditions, where photon loss is a possibility, the resulting gates can still be used to build graph states for one-way quantum computing. In this paper, we describe the RUS method, present possible experimental realizations, and analyze the generation of graph states.},

doi = {10.1103/PHYSREVA.73.0},

journal = {Physical Review. A},

number = 1,

volume = 73,

place = {United States},

year = {Sun Jan 15 00:00:00 EST 2006},

month = {Sun Jan 15 00:00:00 EST 2006}

}