Quantum sensor


The field of quantum sensing deals with the design and engineering of quantum sources (e.g., entangled) and quantum measurements that are able to beat the performance of any classical strategy in a number of technological applications. This can be done with photonic systems[1] or solid state systems.[2]

Quantum sensing utilizes properties of quantum mechanics, such as quantum entanglement, quantum interference, and quantum state squeezing, which have optimized precision and beat current limits in sensor technology and evade the Heisenberg uncertainty principle.[3]

Photonic quantum sensing leverages entanglement, single photons and squeezed states to perform extremely precise measurements. Optical sensing makes use of continuously variable quantum systems such as different degrees of freedom of the electromagnetic field, vibrational modes of solids, and Bose–Einstein condensates.[4] These quantum systems can be probed to characterize an unknown transformation between two quantum states. Several methods are in place to improve photonic sensors' quantum illumination of targets, which have been used to improve detection of weak signals by the use of quantum correlation.[5][6][7][8]

In photonics and quantum optics, quantum sensors are often built on continuously variable systems, i.e., quantum systems characterized by continuous degrees of freedom such as position and momentum quadratures. The basic working mechanism typically relies on optical states of light, often involving quantum mechanical properties such as squeezing or two-mode entanglement.[1] These states are sensitive to physical transformations that are detected by interferometric measurements.[4]

Quantum sensing can also be utilized in non-photonic areas such as spin qubits, trapped ions, and flux qubits.[2] These systems can be compared by physical characteristics to which they respond, for example, trapped ions respond to electrical fields while spin systems will respond to magnetic fields.[2] Trapped Ions are useful in their quantized motional levels which are strongly coupled to the electric field. They have been proposed to study electric field noise above surfaces,[9] and more recently, rotation sensors.[10]

In solid-state physics, a quantum sensor is a quantum device that responds to a stimulus. Usually this refers to a sensor that, which has quantized energy levels, uses quantum coherence to measure a physical quantity, or uses entanglement to improve measurements beyond what can be done with classical sensors.[2] There are 4 criteria for solid-state quantum sensors:[2]

  1. The system has to have discrete, resolvable energy levels.
  2. You can initialize the sensor and you can perform readout (turn on and get answer).
  3. You can coherently manipulate the sensor.
  4. The sensor interacts with a physical quantity and has some response to that quantity.

Ongoing Research and Applications

Quantum Sensors have applications in a wide variety of fields including microscopy, positioning systems, communication technology, electric and magnetic field sensors, as well as geophysical areas of research such as mineral prospecting and seismology.[2] Many measurement devices utilize quantum properties in order to probe measurements such as atomic clocks, superconducting quantum interference devices, and nuclear magnetic resonance spectroscopy.[2][11] With new technological advancements, individual quantum systems can be used as measurement devices, utilizing entanglement, superposition, interference and squeezing to enhance sensitivity and surpass performance of classical strategies.

A good example of an early quantum sensor is an avalanche photodiode (ADP). ADPs have been used to detect entangled photons. With additional cooling and sensor improvements can be used where photomultiplier tubes (PMT) in fields such as medical imaging. APDs, in the form of 2-D and even 3-D stacked arrays, can be used as a direct replacement for conventional sensors based on silicon diodes.[12]

The Defense Advanced Research Projects Agency (DARPA) launched a research program in optical quantum sensors that seeks to exploit ideas from quantum metrology and quantum imaging, such as quantum lithography and the NOON state,[13] in order to achieve these goals with optical sensor systems such as lidar.[14][15][16] The United States judges quantum sensing to be the most mature of quantum technologies for military use, theoretically replacing GPS in areas without coverage or possibly acting with ISR capabilities or detecting submarine or subterranean structures or vehicles, as well as nuclear material.[17]

For photonic systems, current areas of research consider feedback and adaptive protocols. This is an active area of research in discrimination and estimation of bosonic loss.[18]

Injecting squeezed light into interferometers allows for higher sensitivity to weak signals that would be unable to be classically detected.[3] A practical application of quantum sensing is realized in gravitational wave sensing.[19] Gravitational wave detectors, such as LIGO, utilize squeezed light to measure signals below the standard quantum limit.[20] Squeezed light has also been used to detect signals below the standard quantum limit in plasmonic sensors and atomic force microscopy.[21]

Quantum sensing also has the capability to overcome resolution limits, where current issues of vanishing distinguishability between two close frequencies can be overcome by making the projection noise vanish.[22][23] The diminishing projection noise has direct applications in communication protocols and nano-Nuclear Magnetic Resonance.[24][25]

Entanglement can be used to improve upon existing atomic clocks[26] or create more sensitive magnetometers.[27][28] Quantum radar is also an active area of research. Current classical radars can interrogate many target bins while quantum radars are limited to a single polarization or range.[29]


  1. ^ a b Pirandola, S; Bardhan, B. R.; Gehring, T.; Weedbrook, C.; Lloyd, S. (2018). "Advances in photonic quantum sensing". Nature Photonics. 12 (12): 724–733. arXiv:1811.01969. Bibcode:2018NaPho..12..724P. doi:10.1038/s41566-018-0301-6. S2CID 53626745.
  2. ^ a b c d e f g {{Cite Q|Degen, C. L.; Reinhard, F.; Cappellaro, P. (2017). "Quantum sensing". Reviews of Modern Physics. 89 (3): 035002. arXiv:1611.02427. Bibcode:2017RvMP...89c5002D. doi:10.1103/RevModPhys.89.035002. S2CID 2555443.
  3. ^ a b Li, Dong; Gard, Bryan T.; Gao, Yang; Yuan, Chun-Hua; Zhang, Weiping; Lee, Hwang; Dowling, Jonathan P. (December 19, 2016). "Phase sensitivity at the Heisenberg limit in an SU(1,1) interferometer via parity detection". Physical Review A. 94 (6): 063840. arXiv:1603.09019. Bibcode:2016PhRvA..94f3840L. doi:10.1103/PhysRevA.94.063840. S2CID 118404862.
  4. ^ a b Adesso, Gerardo; Ragy, Sammy; Lee, Antony R. (June 2014). "Continuous Variable Quantum Information: Gaussian States and Beyond". Open Systems & Information Dynamics. 21 (1n02): 1440001. arXiv:1401.4679. doi:10.1142/S1230161214400010. S2CID 15318256.
  5. ^ Tan, Si-Hui; Erkmen, Baris I.; Giovannetti, Vittorio; Guha, Saikat; Lloyd, Seth; Maccone, Lorenzo; Pirandola, Stefano; Shapiro, Jeffrey H. (December 18, 2008). "Quantum Illumination with Gaussian States". Physical Review Letters. 101 (25): 253601. arXiv:0810.0534. Bibcode:2008PhRvL.101y3601T. doi:10.1103/PhysRevLett.101.253601. PMID 19113706. S2CID 26890855.
  6. ^ Shapiro, Jeffrey H; Lloyd, Seth (June 24, 2009). "Quantum illumination versus coherent-state target detection". New Journal of Physics. 11 (6): 063045. arXiv:0902.0986. Bibcode:2009NJPh...11f3045S. doi:10.1088/1367-2630/11/6/063045. S2CID 2396896.
  7. ^ Barzanjeh, Sh.; Abdi, M.; Milburn, G. J.; Tombesi, P.; Vitali, D. (September 28, 2012). "Reversible Optical-to-Microwave Quantum Interface". Physical Review Letters. 109 (13): 130503. arXiv:1110.6215. Bibcode:2012PhRvL.109m0503B. doi:10.1103/PhysRevLett.109.130503. PMID 23030075. S2CID 6470118.
  8. ^ Guha, Saikat; Erkmen, Baris I. (November 10, 2009). "Gaussian-state quantum-illumination receivers for target detection". Physical Review A. 80 (5): 052310. arXiv:0911.0950. Bibcode:2009PhRvA..80e2310G. doi:10.1103/PhysRevA.80.052310. S2CID 109058131.
  9. ^ Brownnutt, M.; Kumph, M.; Rabl, P.; Blatt, R. (December 11, 2015). "Ion-trap measurements of electric-field noise near surfaces". Reviews of Modern Physics. 87 (4): 1419–1482. arXiv:1409.6572. Bibcode:2015RvMP...87.1419B. doi:10.1103/RevModPhys.87.1419. S2CID 119008607.
  10. ^ Campbell, W (February 23, 2017). "Rotation sensing with trapped ions". Journal of Physics B. 50 (6): 064002. arXiv:1609.00659. Bibcode:2017JPhB...50f4002C. doi:10.1088/1361-6455/aa5a8f. S2CID 26952809.
  11. ^ Pezzè, Luca; Smerzi, Augusto; Oberthaler, Markus K.; Schmied, Roman; Treutlein, Philipp (September 5, 2018). "Quantum metrology with nonclassical states of atomic ensembles". Reviews of Modern Physics. 90 (3): 035005. arXiv:1609.01609. Bibcode:2018RvMP...90c5005P. doi:10.1103/RevModPhys.90.035005. S2CID 119250709.
  12. ^ Campbell, Joe C. (January 2007). "Recent Advances in Telecommunications Avalanche Photodiodes". Journal of Lightwave Technology. 25 (1): 109–121. Bibcode:2007JLwT...25..109C. doi:10.1109/jlt.2006.888481. S2CID 1398387.
  13. ^ Israel, Yonatan (2014). "Supersensitive Polarization Microscopy Using NOON States of Light". Physical Review Letters. 112 (10): 103604. Bibcode:2014PhRvL.112j3604I. doi:10.1103/PhysRevLett.112.103604. PMID 24679294.
  14. ^ DARPA Quantum Sensor Program.
  15. ^ BROAD AGENCY ANNOUNCEMENT (BAA) 07-22 Quantum Sensors
  16. ^ Zhuang, Quntao; Zhang, Zheshen; Shapiro, Jeffrey H. (October 16, 2017). "Entanglement-enhanced lidars for simultaneous range and velocity measurements". Physical Review A. 96 (4): 040304. arXiv:1705.06793. Bibcode:2017PhRvA..96d0304Z. doi:10.1103/PhysRevA.96.040304. S2CID 54955615.
  17. ^ Kelley M. Sayler (June 7, 2021). Defense Primer: Quantum Technology (PDF) (Report). Congressional Research Service. Retrieved July 22, 2021.
  18. ^ Laurenza, Riccardo; Lupo, Cosmo; Spedalieri, Gaetana; Braunstein, Samuel L.; Pirandola, Stefano (March 1, 2018). "Channel Simulation in Quantum Metrology". Quantum Measurements and Quantum Metrology. 5 (1): 1–12. arXiv:1712.06603. Bibcode:2018QMQM....5....1L. doi:10.1515/qmetro-2018-0001. S2CID 119001470.
  19. ^ Barsotti, Lisa (2014). "Quantum Noise Reduction in the LIGO Gravitational Wave Interferometer with Squeezed States of Light". CLEO: Applications and Technology 2014. p. AW3P.4. doi:10.1364/CLEO_AT.2014.AW3P.4. ISBN 978-1-55752-999-2. S2CID 28876707.
  20. ^ Yu, Haocun; McCuller, L.; Tse, M.; Kijbunchoo, N.; Barsotti, L.; Mavalvala, N. (July 2020). "Quantum correlations between light and the kilogram-mass mirrors of LIGO". Nature. 583 (7814): 43–47. arXiv:2002.01519. Bibcode:2020Natur.583...43Y. doi:10.1038/s41586-020-2420-8. PMID 32612226. S2CID 211031944.
  21. ^ Pooser, Raphael C.; Lawrie, Benjamin (May 20, 2015). "Ultrasensitive measurement of microcantilever displacement below the shot-noise limit". Optica. 2 (5): 393. arXiv:1405.4767. Bibcode:2015Optic...2..393P. doi:10.1364/OPTICA.2.000393. S2CID 118422029.
  22. ^ Nair, Ranjith; Tsang, Mankei (November 4, 2016). "Far-Field Superresolution of Thermal Electromagnetic Sources at the Quantum Limit". Physical Review Letters. 117 (19): 190801. arXiv:1604.00937. Bibcode:2016PhRvL.117s0801N. doi:10.1103/PhysRevLett.117.190801. PMID 27858425. S2CID 25870660.
  23. ^ Tsang, Mankei; Nair, Ranjith; Lu, Xiao-Ming (August 29, 2016). "Quantum Theory of Superresolution for Two Incoherent Optical Point Sources". Physical Review X. 6 (3): 031033. arXiv:1511.00552. Bibcode:2016PhRvX...6c1033T. doi:10.1103/PhysRevX.6.031033. S2CID 32680254.
  24. ^ Maze, J. R.; Stanwix, P. L.; Hodges, J. S.; Hong, S.; Taylor, J. M.; Cappellaro, P.; Jiang, L.; Dutt, M. V. Gurudev; Togan, E.; Zibrov, A. S.; Yacoby, A. (October 2008). "Nanoscale magnetic sensing with an individual electronic spin in diamond". Nature. 455 (7213): 644–647. Bibcode:2008Natur.455..644M. doi:10.1038/nature07279. PMID 18833275. S2CID 136428582.
  25. ^ Kong, Xi; Stark, Alexander; Du, Jiangfeng; McGuinness, Liam P.; Jelezko, Fedor (August 6, 2015). "Towards Chemical Structure Resolution with Nanoscale Nuclear Magnetic Resonance Spectroscopy". Physical Review Applied. 4 (2): 024004. arXiv:1506.05882. Bibcode:2015PhRvP...4b4004K. doi:10.1103/PhysRevApplied.4.024004. S2CID 172297.
  26. ^ Bollinger, J. J .; Itano, Wayne M.; Wineland, D. J.; Heinzen, D. J. (December 1, 1996). "Optimal frequency measurements with maximally correlated states". Physical Review A. 54 (6): R4649–R4652. Bibcode:1996PhRvA..54.4649B. doi:10.1103/physreva.54.r4649. PMID 9914139.
  27. ^ Auzinsh, M.; Budker, D.; Kimball, D. F.; Rochester, S. M.; Stalnaker, J. E.; Sushkov, A. O.; Yashchuk, V. V. (October 19, 2004). "Can a Quantum Nondemolition Measurement Improve the Sensitivity of an Atomic Magnetometer?". Physical Review Letters. 93 (17): 173002. arXiv:physics/0403097. Bibcode:2004PhRvL..93q3002A. doi:10.1103/physrevlett.93.173002. PMID 15525071. S2CID 31287682.
  28. ^ Guillaume, Alexandre; Dowling, Jonathan P. (April 27, 2006). "Heisenberg-limited measurements with superconducting circuits". Physical Review A. 73 (4): 040304(R). arXiv:quant-ph/0512144. Bibcode:2006PhRvA..73d0304G. doi:10.1103/physreva.73.040304. S2CID 33820154.
  29. ^ Lanzagorta, Marco (October 31, 2011). "Quantum Radar". Synthesis Lectures on Quantum Computing. 3 (1): 1–139. doi:10.2200/S00384ED1V01Y201110QMC005.