Abstract

Scalable photonic quantum technologies are based on multiple nested interferometers. To realize this architecture, integrated optical structures are needed to ensure stable, controllable, and repeatable operation. Here we show a key proof-of-principle demonstration of an externally-controlled photonic quantum circuit based upon UV-written waveguide technology. In particular, we present non-classical interference of photon pairs in a Mach-Zehnder interferometer constructed with X couplers in an integrated optical circuit with a thermo-optic phase shifter in one of the interferometer arms.

© 2009 Optical Society of America

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2009 (4)

U. Dorner, R. Demkowicz-Dobrzanski, B. J. Smith, J. S. Lundeen, W. Wasilewski, K. Banaszek, and I. A. Walmsley, "Optimal Quantum Phase Estmation," Phys. Rev. Lett. 102, 040403 (2009).
[PubMed]

B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, "Simplifying quantum logic using higher-dimensional Hilbert spaces," Nat. Phys. 5, 134-140 (2009).

A. S. Clark, J. Fulconis, J. G. Rarity, W. J. Wadsworth, and J. L. O’Brien, "All-optical-fiber polarization-based quantum logic gate," Phys. Rev. A 79, 030303(R) (2009).

J. C. F. Matthews, A. Politi, A. Stefanov, and J. L. O’Brien, "Manipulation of multiphoton entanglement in waveguide quantum circuits," Nat. Photonics 3, 346-350 (2009).

2008 (7)

P. J. Mosley, J. S. Lundeen, B. J. Smith, P. Wasylcyk, A. B. U’Ren, C. Silberhorn, and I. A.Walmsley, "Heralded Generation of Ultrafast Single Photons in Pure Quantum States," Phys. Rev. Lett. 100, 133601 (2008).
[PubMed]

P. J. Mosley, J. S. Lundeen, B. J. Smith, and I. A. Walmsley, "Conditional preparation of single photons using parametric downconversion: a recipe for purity," New J. Phys. 10, 093011 (2008).

A. Politi, M. J. Cryan, J. G. Rarity, S. Yu, and J. L. O’Brien, "Silica-on-Silicon Waveguide Quantum Circuits," Science 320, 646-649 (2008).
[PubMed]

J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
[PubMed]

I. A. Walmsley, "Looking to the Future of Quantum Optics," Science 319, 1211-1213 (2008).
[PubMed]

Z.-S. Yuan, Y.-A. Chen, B. Zhao, S. Chen, J. Schmiedmayer, and J.-W. Pan, "Experimental demonstration of a BDCZ quantum repeater node," Nature 454, 1098-1101 (2008).
[PubMed]

H. J. Kimble, "The Quantum Internet," Nature 453, 1023-1030 (2008).
[PubMed]

2007 (6)

P. Kok, W. J. Munro, K. Nemoto, T. C. Ralph, J. P. Dowling, and G. J. Milburn, "Linear optical quantum computing with photonic qubits," Rev. Mod. Phys. 79, 135-174 (2007).

J. L. O’Brien, "Optical Quantum Computing," Science 318, 1567-1570 (2007).
[PubMed]

N. Gisin and R. Thew, "Quantum Communication," Nat. Photonics 1, 165-171 (2007).

C. Y. Lu, X.-Q. Zhou, O. Guhne, W.-B. Gao, J. Zhang, Z.-S. Yuan, A. Goebel, T. Yang, and J.-W. Pan, "Experimental entanglement of six photons in graph states," Nat. Phys. 3, 91-95 (2007).

B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, "Beating the Standard Quantum Limit with Four-Entangled Photons," Science 316, 726-729 (2007).
[PubMed]

2006 (2)

2005 (7)

F. Durr and H. Renner, "Analytical Design of X-Couplers," J. Lightwave Technol. 23(2), 876-885 (2005).

I. A. Walmsley and M. G. Raymer, "Toward Quantum-Information Processing with Photons," Science 307, 1733-1734 (2005).
[PubMed]

N. K. Langford, T. J. Weinhold, R. Prevedel, K. J. Resch, A. Gilchrist, J. L. O’Brien, G. J. Pryde, and A. G. White, "Demonstration of a Simple Entangling Optical Gate and its use in Bell-State Analysis," Phys. Rev. Lett. 95, 210504 (2005).
[PubMed]

N. Kiesel, C. Schmid, U. Weber, R. Ursin, and H. Weinfurter, "Linear Optics controlled-phase gate made simple," Phys. Rev. Lett. 95, 210505 (2005).
[PubMed]

R. Okamoto, H. F. Hofmann, S. Takeuchi, and K. Sasaki, "Demonstration of and Optical Quantum Controlled-NOT Gate withtout path interference," Phys. Rev. Lett. 95, 210506 (2005).
[PubMed]

P. Walther, K. J. Resch, T. Rudolph, E. Schenck, H. Weinfurter, V. Vedral, M. Aspelmeyer, and A. Zeilinger, "Experimental one-way quantum computing," Nature 434, 169-176 (2005).
[PubMed]

N. Kiesel, C. Schmid, U. Weber, G. Toth, O. Guhne, R. Ursin, and H. Weinfurter, "Experimental Analysis of a Four-Qubit Photon Cluster State," Phys. Rev. Lett. 95, 210502 (2005).
[PubMed]

2004 (5)

V. Giovannetti, S. Lloyd, and L. Maccone, "Quantum-enhanced measurements: Beating the standard quantum limit," Science 306, 1330-1336 (2004).
[PubMed]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, "Super-Resolving Phase Measurements with a Multiphoton Entangled State," Nature 429, 161-164 (2004).
[PubMed]

P. Walther, J.-W. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, "De Broglie wavelength of a non-local four-photon state," Nature 429, 158-161 (2004).
[PubMed]

J. O’Brien, G. J. Pryde, A. Gilchrist, D. F. V. James, N. K. Langford, T. C. Ralph, and A. G. White, "Quantum Process Tomography of a Controlled-NOT Gate," Phys. Rev. Lett. 93, 080502 (2004).
[PubMed]

S. Gasparoni, J.-W. Pan, P. Walther, T. Rudolph, and A. Zeilinger, "Realization of a Photonic Controlled-NOT Gate sufficient for Quantum Computation," Phys. Rev. Lett. 93, 020504 (2004).
[PubMed]

2003 (3)

T. B. Pittman, M. J. Fitch, B. C. Jacobs, and J. D. Franson, "Experimental controlled-NOT logic gate for single photons in the coincidence basis," Phys. Rev. A 68, 032316 (2003).

J. L. O’Brien, G. J. Pryde, A. G. White, T. C. Ralph, and D. Branning, "Demonstration of an all-optical quantum controlled-NOT gate," Nature 426, 264-267 (2003).
[PubMed]

P. Tandon and H. Boek, "Experimental and theoretical studies of flame hydrolosis deposition process for making glasses for optical planar devices," J. Non-Crystal.Solids 317, 275-289 (2003).

2002 (2)

G. D. Emmerson, S. P. Watt, C. B. E. Gawith, V. Albanis, M. Ibsen, R. B. Williams, and P. G. R. Smith, "Fabrication of directly UV-written channel waveguides with simultaneously defined integral Bragg gratings," Electron. Lett. 38, 1531-1532 (2002).

N. Gisin, G. Ribordy,W. Tittel, and H. Zbinden, "Quantum Cryptography," Rev. Mod. Phys. 74, 145-195 (2002).

2001 (2)

L. M. Duan, M. D. Lukin, J. I. Cirac, and P. Zoller, "Long-distance quantum communciation with atomic ensembles and linear optics," Nature 414, 413-418 (2001).
[PubMed]

R. Laflamme, G. J. Milburn, and E. Knill, "A scheme for efficient quantum computation with linear optics," Nature 409, 46-52 (2001).
[PubMed]

1994 (2)

M. Reck, A. Zeilinger, H. J. Bernstein, and P. Bertani, "Experimental realization of any discrete unitary operator," Phys. Rev. Lett. 73, 58-61 (1994).
[PubMed]

M. Svalgaard, C. V. Poulsen, A. Bjarklev, and O. Poulsen, "UV-writing of buried single-mode channel waveguides in Ge-doped silica films," Electron. Lett. 30, 1401-1402 (1994).

1991 (1)

A. K. Ekert, "Quantum Cryptography based on Bell’s Theorem," Phys. Rev. Lett. 67, 661-663 (1991).
[PubMed]

1990 (1)

J. G. Rarity, P. R. Tapster, E. Jakeman, T. Larchuk, R. A. Campos, M. C. Teich, and B. E. Saleh, "Two-photon interference in a Mach-Zehnder interferometer," Phys. Rev. Lett. 65, 1348-1351 (1990).
[PubMed]

1987 (1)

C. K. Hong, Z. Y. Ou, and L. Mandel, "Measurement of subpicosecond time intervals between two photons by interference," Phys. Rev. Lett. 59, 2044-2046 (1987).
[PubMed]

1983 (1)

S. Wiesner, "Conjugate coding," SIGACT News 15, 78-88 (1983).

Adikan, F. R. M.

Ahmad, H.

Albanis, V.

G. D. Emmerson, S. P. Watt, C. B. E. Gawith, V. Albanis, M. Ibsen, R. B. Williams, and P. G. R. Smith, "Fabrication of directly UV-written channel waveguides with simultaneously defined integral Bragg gratings," Electron. Lett. 38, 1531-1532 (2002).

Almeida, M. P.

B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, "Simplifying quantum logic using higher-dimensional Hilbert spaces," Nat. Phys. 5, 134-140 (2009).

Altepeter, J. B.

J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
[PubMed]

Aspelmeyer, M.

P. Walther, K. J. Resch, T. Rudolph, E. Schenck, H. Weinfurter, V. Vedral, M. Aspelmeyer, and A. Zeilinger, "Experimental one-way quantum computing," Nature 434, 169-176 (2005).
[PubMed]

P. Walther, J.-W. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, "De Broglie wavelength of a non-local four-photon state," Nature 429, 158-161 (2004).
[PubMed]

Banaszek, K.

U. Dorner, R. Demkowicz-Dobrzanski, B. J. Smith, J. S. Lundeen, W. Wasilewski, K. Banaszek, and I. A. Walmsley, "Optimal Quantum Phase Estmation," Phys. Rev. Lett. 102, 040403 (2009).
[PubMed]

Barbieri, M.

B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, "Simplifying quantum logic using higher-dimensional Hilbert spaces," Nat. Phys. 5, 134-140 (2009).

B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

Bernstein, H. J.

M. Reck, A. Zeilinger, H. J. Bernstein, and P. Bertani, "Experimental realization of any discrete unitary operator," Phys. Rev. Lett. 73, 58-61 (1994).
[PubMed]

Bertani, P.

M. Reck, A. Zeilinger, H. J. Bernstein, and P. Bertani, "Experimental realization of any discrete unitary operator," Phys. Rev. Lett. 73, 58-61 (1994).
[PubMed]

Bjarklev, A.

M. Svalgaard, C. V. Poulsen, A. Bjarklev, and O. Poulsen, "UV-writing of buried single-mode channel waveguides in Ge-doped silica films," Electron. Lett. 30, 1401-1402 (1994).

Boek, H.

P. Tandon and H. Boek, "Experimental and theoretical studies of flame hydrolosis deposition process for making glasses for optical planar devices," J. Non-Crystal.Solids 317, 275-289 (2003).

Branning, D.

J. L. O’Brien, G. J. Pryde, A. G. White, T. C. Ralph, and D. Branning, "Demonstration of an all-optical quantum controlled-NOT gate," Nature 426, 264-267 (2003).
[PubMed]

Campos, R. A.

J. G. Rarity, P. R. Tapster, E. Jakeman, T. Larchuk, R. A. Campos, M. C. Teich, and B. E. Saleh, "Two-photon interference in a Mach-Zehnder interferometer," Phys. Rev. Lett. 65, 1348-1351 (1990).
[PubMed]

Chen, J.

J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
[PubMed]

Chen, S.

Z.-S. Yuan, Y.-A. Chen, B. Zhao, S. Chen, J. Schmiedmayer, and J.-W. Pan, "Experimental demonstration of a BDCZ quantum repeater node," Nature 454, 1098-1101 (2008).
[PubMed]

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A. Politi, M. J. Cryan, J. G. Rarity, S. Yu, and J. L. O’Brien, "Silica-on-Silicon Waveguide Quantum Circuits," Science 320, 646-649 (2008).
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A. S. Clark, J. Fulconis, J. G. Rarity, W. J. Wadsworth, and J. L. O’Brien, "All-optical-fiber polarization-based quantum logic gate," Phys. Rev. A 79, 030303(R) (2009).

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C. Y. Lu, X.-Q. Zhou, O. Guhne, W.-B. Gao, J. Zhang, Z.-S. Yuan, A. Goebel, T. Yang, and J.-W. Pan, "Experimental entanglement of six photons in graph states," Nat. Phys. 3, 91-95 (2007).

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B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, "Simplifying quantum logic using higher-dimensional Hilbert spaces," Nat. Phys. 5, 134-140 (2009).

B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

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J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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N. Kiesel, C. Schmid, U. Weber, G. Toth, O. Guhne, R. Ursin, and H. Weinfurter, "Experimental Analysis of a Four-Qubit Photon Cluster State," Phys. Rev. Lett. 95, 210502 (2005).
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J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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J. G. Rarity, P. R. Tapster, E. Jakeman, T. Larchuk, R. A. Campos, M. C. Teich, and B. E. Saleh, "Two-photon interference in a Mach-Zehnder interferometer," Phys. Rev. Lett. 65, 1348-1351 (1990).
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J. O’Brien, G. J. Pryde, A. Gilchrist, D. F. V. James, N. K. Langford, T. C. Ralph, and A. G. White, "Quantum Process Tomography of a Controlled-NOT Gate," Phys. Rev. Lett. 93, 080502 (2004).
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N. Kiesel, C. Schmid, U. Weber, G. Toth, O. Guhne, R. Ursin, and H. Weinfurter, "Experimental Analysis of a Four-Qubit Photon Cluster State," Phys. Rev. Lett. 95, 210502 (2005).
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Kumar, P.

J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

N. K. Langford, T. J. Weinhold, R. Prevedel, K. J. Resch, A. Gilchrist, J. L. O’Brien, G. J. Pryde, and A. G. White, "Demonstration of a Simple Entangling Optical Gate and its use in Bell-State Analysis," Phys. Rev. Lett. 95, 210504 (2005).
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B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

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J. G. Rarity, P. R. Tapster, E. Jakeman, T. Larchuk, R. A. Campos, M. C. Teich, and B. E. Saleh, "Two-photon interference in a Mach-Zehnder interferometer," Phys. Rev. Lett. 65, 1348-1351 (1990).
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J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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U. Dorner, R. Demkowicz-Dobrzanski, B. J. Smith, J. S. Lundeen, W. Wasilewski, K. Banaszek, and I. A. Walmsley, "Optimal Quantum Phase Estmation," Phys. Rev. Lett. 102, 040403 (2009).
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P. J. Mosley, J. S. Lundeen, B. J. Smith, P. Wasylcyk, A. B. U’Ren, C. Silberhorn, and I. A.Walmsley, "Heralded Generation of Ultrafast Single Photons in Pure Quantum States," Phys. Rev. Lett. 100, 133601 (2008).
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J. C. F. Matthews, A. Politi, A. Stefanov, and J. L. O’Brien, "Manipulation of multiphoton entanglement in waveguide quantum circuits," Nat. Photonics 3, 346-350 (2009).

Medic, M.

J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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P. Kok, W. J. Munro, K. Nemoto, T. C. Ralph, J. P. Dowling, and G. J. Milburn, "Linear optical quantum computing with photonic qubits," Rev. Mod. Phys. 79, 135-174 (2007).

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M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, "Super-Resolving Phase Measurements with a Multiphoton Entangled State," Nature 429, 161-164 (2004).
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P. J. Mosley, J. S. Lundeen, B. J. Smith, and I. A. Walmsley, "Conditional preparation of single photons using parametric downconversion: a recipe for purity," New J. Phys. 10, 093011 (2008).

P. J. Mosley, J. S. Lundeen, B. J. Smith, P. Wasylcyk, A. B. U’Ren, C. Silberhorn, and I. A.Walmsley, "Heralded Generation of Ultrafast Single Photons in Pure Quantum States," Phys. Rev. Lett. 100, 133601 (2008).
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P. Kok, W. J. Munro, K. Nemoto, T. C. Ralph, J. P. Dowling, and G. J. Milburn, "Linear optical quantum computing with photonic qubits," Rev. Mod. Phys. 79, 135-174 (2007).

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T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, "Beating the Standard Quantum Limit with Four-Entangled Photons," Science 316, 726-729 (2007).
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J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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J. O’Brien, G. J. Pryde, A. Gilchrist, D. F. V. James, N. K. Langford, T. C. Ralph, and A. G. White, "Quantum Process Tomography of a Controlled-NOT Gate," Phys. Rev. Lett. 93, 080502 (2004).
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B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, "Simplifying quantum logic using higher-dimensional Hilbert spaces," Nat. Phys. 5, 134-140 (2009).

A. S. Clark, J. Fulconis, J. G. Rarity, W. J. Wadsworth, and J. L. O’Brien, "All-optical-fiber polarization-based quantum logic gate," Phys. Rev. A 79, 030303(R) (2009).

J. C. F. Matthews, A. Politi, A. Stefanov, and J. L. O’Brien, "Manipulation of multiphoton entanglement in waveguide quantum circuits," Nat. Photonics 3, 346-350 (2009).

A. Politi, M. J. Cryan, J. G. Rarity, S. Yu, and J. L. O’Brien, "Silica-on-Silicon Waveguide Quantum Circuits," Science 320, 646-649 (2008).
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T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, "Beating the Standard Quantum Limit with Four-Entangled Photons," Science 316, 726-729 (2007).
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R. Okamoto, H. F. Hofmann, S. Takeuchi, and K. Sasaki, "Demonstration of and Optical Quantum Controlled-NOT Gate withtout path interference," Phys. Rev. Lett. 95, 210506 (2005).
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Z.-S. Yuan, Y.-A. Chen, B. Zhao, S. Chen, J. Schmiedmayer, and J.-W. Pan, "Experimental demonstration of a BDCZ quantum repeater node," Nature 454, 1098-1101 (2008).
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C. Y. Lu, X.-Q. Zhou, O. Guhne, W.-B. Gao, J. Zhang, Z.-S. Yuan, A. Goebel, T. Yang, and J.-W. Pan, "Experimental entanglement of six photons in graph states," Nat. Phys. 3, 91-95 (2007).

P. Walther, J.-W. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, "De Broglie wavelength of a non-local four-photon state," Nature 429, 158-161 (2004).
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S. Gasparoni, J.-W. Pan, P. Walther, T. Rudolph, and A. Zeilinger, "Realization of a Photonic Controlled-NOT Gate sufficient for Quantum Computation," Phys. Rev. Lett. 93, 020504 (2004).
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T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, "Beating the Standard Quantum Limit with Four-Entangled Photons," Science 316, 726-729 (2007).
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U. Dorner, R. Demkowicz-Dobrzanski, B. J. Smith, J. S. Lundeen, W. Wasilewski, K. Banaszek, and I. A. Walmsley, "Optimal Quantum Phase Estmation," Phys. Rev. Lett. 102, 040403 (2009).
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N. Kiesel, C. Schmid, U. Weber, R. Ursin, and H. Weinfurter, "Linear Optics controlled-phase gate made simple," Phys. Rev. Lett. 95, 210505 (2005).
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B. P. Lanyon, T. J. Weinhold, N. K. Langford, M. Barbieri, D. F. V. James, A. Gilchrist, and A. G. White, "Experimental Demonstration of a Compiled Version of Shor’s Algorithm with Quantum Entanglement," Phys. Rev. Lett. 99, 250505 (2007).

N. K. Langford, T. J. Weinhold, R. Prevedel, K. J. Resch, A. Gilchrist, J. L. O’Brien, G. J. Pryde, and A. G. White, "Demonstration of a Simple Entangling Optical Gate and its use in Bell-State Analysis," Phys. Rev. Lett. 95, 210504 (2005).
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A. Politi, M. J. Cryan, J. G. Rarity, S. Yu, and J. L. O’Brien, "Silica-on-Silicon Waveguide Quantum Circuits," Science 320, 646-649 (2008).
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Z.-S. Yuan, Y.-A. Chen, B. Zhao, S. Chen, J. Schmiedmayer, and J.-W. Pan, "Experimental demonstration of a BDCZ quantum repeater node," Nature 454, 1098-1101 (2008).
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P. Walther, K. J. Resch, T. Rudolph, E. Schenck, H. Weinfurter, V. Vedral, M. Aspelmeyer, and A. Zeilinger, "Experimental one-way quantum computing," Nature 434, 169-176 (2005).
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Appl. Opt. (1)

Electron. Lett. (2)

M. Svalgaard, C. V. Poulsen, A. Bjarklev, and O. Poulsen, "UV-writing of buried single-mode channel waveguides in Ge-doped silica films," Electron. Lett. 30, 1401-1402 (1994).

G. D. Emmerson, S. P. Watt, C. B. E. Gawith, V. Albanis, M. Ibsen, R. B. Williams, and P. G. R. Smith, "Fabrication of directly UV-written channel waveguides with simultaneously defined integral Bragg gratings," Electron. Lett. 38, 1531-1532 (2002).

IEEE Photon. Technol. Lett. (1)

D. O. Kundys, J. C. Gates, S. Dasgupta, C. B. E. Gawith, and P. G. R. Smith, "Use of Cross-Couplers to Decrease Size of UV Written Photonic Circuits," IEEE Photon. Technol. Lett. (to be published).

J. Lightwave Technol. (1)

Nat. Photonics (2)

J. C. F. Matthews, A. Politi, A. Stefanov, and J. L. O’Brien, "Manipulation of multiphoton entanglement in waveguide quantum circuits," Nat. Photonics 3, 346-350 (2009).

N. Gisin and R. Thew, "Quantum Communication," Nat. Photonics 1, 165-171 (2007).

Nat. Phys. (2)

C. Y. Lu, X.-Q. Zhou, O. Guhne, W.-B. Gao, J. Zhang, Z.-S. Yuan, A. Goebel, T. Yang, and J.-W. Pan, "Experimental entanglement of six photons in graph states," Nat. Phys. 3, 91-95 (2007).

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A. S. Clark, J. Fulconis, J. G. Rarity, W. J. Wadsworth, and J. L. O’Brien, "All-optical-fiber polarization-based quantum logic gate," Phys. Rev. A 79, 030303(R) (2009).

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J. Chen, J. B. Altepeter, M. Medic, K. F. Lee, B. Gokden, R. H. Hadfield, S. W. Nam, and P. Kumar, "Demonstration of a Quantum Controlled-NOT Gate in the Telecommunications Band," Phys. Rev. Lett. 100, 133603 (2008).
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G. D. Marshall, A. Politi, J. C. F. Matthews, P. Dekker,M. Ams, M. J. Withford, and J. L. O’Brien, "Laser written photonic quantum circuits," arXiv:0902.4357v1.

Optical-fiber-based quantum logic gates have been recently demonstrated [38, 39]. Such gates will play an important role in quantum communications, but seem limited to a few gates due to classical phase stability, rather than computational tasks with several cascaded gate operations.

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Figures (4)

Fig. 1.
Fig. 1.

Schematic of the UV-waveguide writing process and their structure (inset).

Fig. 2.
Fig. 2.

Experimental setup. Horizontally and vertically polarized photon pairs created by SPDC pass through an interference filter (IF) prior to being separated by a polarizing beam splitter (PBS). A temporal delay line (τ) in one of the photon paths controls the relative arrival time of the photons to the MZI. Half and quarter wave plate pairs (HWP and QWP) ensure the photons coupled into single-mode fibers (SMFs) arrive at the waveguide with identical polarization states. A computer-controlled voltage supply (V) controls the relative phase, ϕ, between the interferometer arms. The outputs of the interferometer are sent to Si avalanche photodiodes (APDs). The singles and coincidence count rates are monitored by field-programmable gate array (FPGA) electronics connected to a computer. Inset shows a schematic of the setup.

Fig. 3.
Fig. 3.

Two-photon HOM interference through a waveguide MZI with the phase (φ) tuned to act as a 50:50 beam splitter. Plots show (a) measured coincidence count rate (79±1% visibility) and (b) background subtracted coincidence count rate (95.0±1.4% visibility) as a function of the relative arrival time of photons to the beam splitter, τ. Error bars are calculated assuming Poisson count statistics and propagating errors for the background subtraction. The blue line is a Gaussian fit.

Fig. 4.
Fig. 4.

Two-photon N00N interference through a waveguide MZI as a function of the phase induced by the thermo-optic phase shifter. Plots show (a) raw measured coincidence count rate (78.9±3% visibility) and (b) background subtracted coincidence count rate (88±3% visibility) at zero time delay. Error bars are calculated assuming Poisson count statistics and propagating errors for the background subtraction. The blue line is a fit to Eq. (3).

Equations (3)

Equations on this page are rendered with MathJax. Learn more.

1,1(2,00,2) 2 ,
(2,00,2)2(2,0ei2ϕ0,2)2,
R1,1(ϕ)=R0{1+Acos[2(ϕ+ϕ0)]}.

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