V. Giovannetti, S. Lloyd, and L. Maccone, “Advances in quantum metrology,” Nat. Photonics5(4), 222–229 (2011).

[CrossRef]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

F. Marquardt and S. Girvin, “Optomechanics,” Physics2, 40 (2009).

[CrossRef]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super-resolving phase measurements with a multiphoton entangled state,” Nature429(6988), 161–164 (2004).

[CrossRef]
[PubMed]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

D. V. Korobkin and E. Yablonovitch, “Two-fold spatial resolution enhancement by two-photon exposure of photographic film,” Opt. Eng.41, 1729–1732 (2002).

[CrossRef]

O. Steuernagel, “de Broglie wavelength reduction for a multiphoton wave packet,” Phys. Rev. A65, 033820 (2002).

[CrossRef]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

B. C. Barish and R. Weiss, “LIGO and the detection of gravitational waves,” Phys. Today52(10), 44–50 (1999).

[CrossRef]

S. Braunstein and C. Caves, “Statistical distance and the geometry of quantum states,” Phys. Rev. Lett.72(22), 3439–3443 (1994).

[CrossRef]
[PubMed]

R. Campos, B. Saleh, and M. Teich, “Quantum-mechanical lossless beam splitter: SU(2) symmetry and photon statistics,” Phys. Rev. A40(3), 1371–1384 (1989).

[CrossRef]
[PubMed]

R. A. Fisher, “Theory of statistical estimation,” Mathematical Proceedings of the Cambridge Philosophical Society22(05), 700–725 (1925).

[CrossRef]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

B. C. Barish and R. Weiss, “LIGO and the detection of gravitational waves,” Phys. Today52(10), 44–50 (1999).

[CrossRef]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

S. Braunstein and C. Caves, “Statistical distance and the geometry of quantum states,” Phys. Rev. Lett.72(22), 3439–3443 (1994).

[CrossRef]
[PubMed]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

R. Campos, B. Saleh, and M. Teich, “Quantum-mechanical lossless beam splitter: SU(2) symmetry and photon statistics,” Phys. Rev. A40(3), 1371–1384 (1989).

[CrossRef]
[PubMed]

S. Braunstein and C. Caves, “Statistical distance and the geometry of quantum states,” Phys. Rev. Lett.72(22), 3439–3443 (1994).

[CrossRef]
[PubMed]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

R. A. Fisher, “Theory of statistical estimation,” Mathematical Proceedings of the Cambridge Philosophical Society22(05), 700–725 (1925).

[CrossRef]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

V. Giovannetti, S. Lloyd, and L. Maccone, “Advances in quantum metrology,” Nat. Photonics5(4), 222–229 (2011).

[CrossRef]

F. Marquardt and S. Girvin, “Optomechanics,” Physics2, 40 (2009).

[CrossRef]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

D. V. Korobkin and E. Yablonovitch, “Two-fold spatial resolution enhancement by two-photon exposure of photographic film,” Opt. Eng.41, 1729–1732 (2002).

[CrossRef]

V. Giovannetti, S. Lloyd, and L. Maccone, “Advances in quantum metrology,” Nat. Photonics5(4), 222–229 (2011).

[CrossRef]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super-resolving phase measurements with a multiphoton entangled state,” Nature429(6988), 161–164 (2004).

[CrossRef]
[PubMed]

V. Giovannetti, S. Lloyd, and L. Maccone, “Advances in quantum metrology,” Nat. Photonics5(4), 222–229 (2011).

[CrossRef]

F. Marquardt and S. Girvin, “Optomechanics,” Physics2, 40 (2009).

[CrossRef]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super-resolving phase measurements with a multiphoton entangled state,” Nature429(6988), 161–164 (2004).

[CrossRef]
[PubMed]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

R. Campos, B. Saleh, and M. Teich, “Quantum-mechanical lossless beam splitter: SU(2) symmetry and photon statistics,” Phys. Rev. A40(3), 1371–1384 (1989).

[CrossRef]
[PubMed]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

G. M. Gehring, H. Shin, R. Boyd, C. M. Kim, and B. S. Ham, “Tunable optical time delay of quantum signals using a prism pair,” Opt. Express18(18), 19156–19162 (2010).

[CrossRef]
[PubMed]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super-resolving phase measurements with a multiphoton entangled state,” Nature429(6988), 161–164 (2004).

[CrossRef]
[PubMed]

O. Steuernagel, “de Broglie wavelength reduction for a multiphoton wave packet,” Phys. Rev. A65, 033820 (2002).

[CrossRef]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]

R. Campos, B. Saleh, and M. Teich, “Quantum-mechanical lossless beam splitter: SU(2) symmetry and photon statistics,” Phys. Rev. A40(3), 1371–1384 (1989).

[CrossRef]
[PubMed]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

B. C. Barish and R. Weiss, “LIGO and the detection of gravitational waves,” Phys. Today52(10), 44–50 (1999).

[CrossRef]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

D. V. Korobkin and E. Yablonovitch, “Two-fold spatial resolution enhancement by two-photon exposure of photographic film,” Opt. Eng.41, 1729–1732 (2002).

[CrossRef]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

F. Zernike, “Phase contrast, a new method for the microscopic observation of transparent objects,” Physica9(7), 686–698 (1942).

[CrossRef]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

R. A. Fisher, “Theory of statistical estimation,” Mathematical Proceedings of the Cambridge Philosophical Society22(05), 700–725 (1925).

[CrossRef]

V. Giovannetti, S. Lloyd, and L. Maccone, “Advances in quantum metrology,” Nat. Photonics5(4), 222–229 (2011).

[CrossRef]

M. W. Mitchell, J. S. Lundeen, and A. M. Steinberg, “Super-resolving phase measurements with a multiphoton entangled state,” Nature429(6988), 161–164 (2004).

[CrossRef]
[PubMed]

P. Walther, J. Pan, M. Aspelmeyer, R. Ursin, S. Gasparoni, and A. Zeilinger, “de Broglie wavelength of a nonlocal four-photon state,” Nature429(6988), 158–161 (2004).

[CrossRef]
[PubMed]

B. L. Higgins, D. W. Berry, S. D. Bartlett, H. M. Wiseman, and G. J. Pryde, “Entanglement-free Heisenberg-limited phase estimation,” Nature450(7168), 393–396 (2007).

[CrossRef]
[PubMed]

D. V. Korobkin and E. Yablonovitch, “Two-fold spatial resolution enhancement by two-photon exposure of photographic film,” Opt. Eng.41, 1729–1732 (2002).

[CrossRef]

R. Campos, B. Saleh, and M. Teich, “Quantum-mechanical lossless beam splitter: SU(2) symmetry and photon statistics,” Phys. Rev. A40(3), 1371–1384 (1989).

[CrossRef]
[PubMed]

O. Steuernagel, “de Broglie wavelength reduction for a multiphoton wave packet,” Phys. Rev. A65, 033820 (2002).

[CrossRef]

H. Shin, K. W. C. Chan, H. J. Chang, and R. W. Boyd, “Quantum spatial superresolution by optical centroid measurements,” Phys. Rev. Lett.107, 083603 (2011).

[CrossRef]
[PubMed]

S. Braunstein and C. Caves, “Statistical distance and the geometry of quantum states,” Phys. Rev. Lett.72(22), 3439–3443 (1994).

[CrossRef]
[PubMed]

K. J. Resch, K. L. Pregnell, R. Prevedel, A. Gilchrist, G. J. Pryde, J. L. O’Brien, and A. G. White, “Time-reversal and super-resolving phase measurements,” Phys. Rev. Lett.98(22), 0223601 (2007).

[CrossRef]

N. Thomas-Peter, B. Smith, A. Datta, L. Zhang, U. Dorner, and I. Walmsley, “Real-world quantum sensors: evaluating resources for precision measurement,” Phys. Rev. Lett.107(11), 0113603 (2011).

[CrossRef]

A. N. Boto, P. Kok, D. S. Abrams, S. L. Braunstein, C. P. Williams, and J. P. Dowling, “Quantum interferometric optical lithography: exploiting entanglement to beat the diffraction limit,” Phys. Rev. Lett.85(13), 2733–2736 (2000).

[CrossRef]
[PubMed]

B. C. Barish and R. Weiss, “LIGO and the detection of gravitational waves,” Phys. Today52(10), 44–50 (1999).

[CrossRef]

F. Zernike, “Phase contrast, a new method for the microscopic observation of transparent objects,” Physica9(7), 686–698 (1942).

[CrossRef]

F. Marquardt and S. Girvin, “Optomechanics,” Physics2, 40 (2009).

[CrossRef]

T. Nagata, R. Okamoto, J. L. O’Brien, K. Sasaki, and S. Takeuchi, “Beating the standard quantum limit with four-entangled photons,” Science316(5825), 726–729 (2007).

[CrossRef]
[PubMed]