Current Science

Open Access Open Access  Restricted Access Subscription Access

Weak Measurements: Typical Weak and Superweak Values


Affiliations
1 Department of Physics, Indian Institute of Technology, Kharagpur 721 302, India
 

Weak value is a physical property of a quantum system which manifests itself through a weak measurement using different pre- and post-selected ensembles of the system. The weak values of an operator may differ significantly from its eigenvalues and can even lie outside the spectrum if it is bound: they can be 'superweak'. The latter, originating due to a coherent superposition of waves, may appear as a 'supershift' on the measuring device. This property has potential application in the amplification and detection of extremely weak signals.

Keywords

Eigenvalue, Ensemble, Quantum System, Weak Measurement.
User
Notifications
Font Size

  • Aharonov, Y., Bergmann, P. G. and Lebowitz, J. L., Time symmetry in the quantum process of measurement. Phys. Rev. B, 1964, 134, B1410–B1416.

  • Aharonov, Y., Albert, D. and Vaidman, L., How the results of a measurement of a component of the spin of a spin-1/2 particle can turn out to be 100. Phys. Rev. Lett., 1988, 60(14), 1351–1354.

  • Aharonov, Y. and Vaidman, L., Properties of a quantum system during the time interval between two measurements. Phys. Rev. A, 1990, 41(1), 11–20.

  • Aharonov, Y., Popescu, S., Rohrlich, D. and Vaidman, L., Measurements, errors, and negative kinetic energy. Phys. Rev. A, 1993, 48(6), 4084–4090.

  • Steinberg, A. M., A light touch. Nature, 2010, 463(7283), 890– 891.

  • Popescu, S., Viewpoint: weak measurements just got stronger. Physics, 2009, 2, 32-1 to 32-3.

  • Berry, M. V. and Shukla, P., Typical weak and superweak values. J. Phys. A, 2010, 43(35), 354024-1 to 354024-9.

  • Berry, M. V., Dennis, M. R., McRoberts, B. and Shukla, P., Weak value distributions for spin 1/2. J. Phys. A, 2011, 44(20), 2053011 to 205301-8.

  • Berry, M. V. and Shukla, P., Pointer supershifts and superoscillations in weak measurements. J. Phys. A, 2012, 45(1), 015301-1 to 015301-14.

  • Berry, M. V. and Dennis, M. R., Natural superoscillations in monochromatic waves in D dimensions. J. Phys. A, 2009, 42(2), 022003-1 to 022003-8.

  • Hosten, O. and Kwiat, P., Observation of the spin Hall effect of light via weak measurements. Science, 2008, 319(5864), 787–790.

  • Ben Dixon, P., Starling, D. J., Jordan, A. N. and Howell, J. C., Ultrasensitive beam deflection measurement via interferometric weak value amplification. Phys. Rev. Lett., 2009, 102(17), 173601-1 to 173601-4.

  • Berry, M. V., Brunner, N., Popescu, S. and Shukla, P., Can apparent superluminal neutrino speeds be explained as a quantum weak measurement. J. Phys. A, 2011, 44(49), 492001-1 to 492001-5.

  • Williams, N. S. and Jordan, A. N., Weak values and the Leggett– Garg inequality in solid-state qubits. Phys. Rev. Lett., 2008, 100(2), 026804-1 to 026804-4.

  • Hardy, L., Quantum mechanics, local realistic theories, and Lorentz-invariant realistic theories. Phys. Rev. Lett., 1992, 68(20), 2981–2984; Revisiting Hardy’s paradox: counterfactual statements, real measurements, entanglement and weak values. Phys. Lett. A, 2002, 301(3–4), 130–138.

  • Rohrlich, D. and Aharonov, Y., Cherenkov radiation of superluminal particles. Phys. Rev. A, 2002, 66(4), 042102-1 to 042102-7.


Abstract Views: 221

PDF Views: 74




  • Weak Measurements: Typical Weak and Superweak Values

Abstract Views: 221  |  PDF Views: 74

Authors

Pragya Shukla
Department of Physics, Indian Institute of Technology, Kharagpur 721 302, India

Abstract


Weak value is a physical property of a quantum system which manifests itself through a weak measurement using different pre- and post-selected ensembles of the system. The weak values of an operator may differ significantly from its eigenvalues and can even lie outside the spectrum if it is bound: they can be 'superweak'. The latter, originating due to a coherent superposition of waves, may appear as a 'supershift' on the measuring device. This property has potential application in the amplification and detection of extremely weak signals.

Keywords


Eigenvalue, Ensemble, Quantum System, Weak Measurement.

References





DOI: https://doi.org/10.18520/cs%2Fv109%2Fi11%2F2039-2043