Quantum sensor

Source: Wikipedia, the free encyclopedia.

Within

quantum interference, and quantum state squeezing, which have optimized precision and beat current limits in sensor technology.[1]
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.[2] This can be done with photonic systems[3] or solid state systems.[4]

Characteristics

In photonics and quantum optics, 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.[5] 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.[6][7][8][9][10]

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.[3] These states are sensitive to physical transformations that are detected by interferometric measurements.[5]

Quantum sensing can also be utilized in non-photonic areas such as spin qubits, trapped ions, flux qubits,[4] and nanoparticles.[11] 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.[4] 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,[12] and more recently, rotation sensors.[13]

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.[4] There are 4 criteria for solid-state quantum sensors:[4]

  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.


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.[4] Many measurement devices utilize quantum properties in order to probe measurements such as atomic clocks, superconducting quantum interference devices, and nuclear magnetic resonance spectroscopy.[4][14] 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 (APD). APDs 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.[15]

The

GPS in areas without coverage or possibly acting with ISR capabilities or detecting submarine or subterranean structures or vehicles, as well as nuclear material.[20]

Photonic quantum sensors, microscopy and gravitational wave detectors

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.[21]

Injecting squeezed light into interferometers allows for higher sensitivity to weak signals that would be unable to be classically detected.[1] A practical application of quantum sensing is realized in gravitational wave sensing.[22] Gravitational wave detectors, such as LIGO, utilize squeezed light to measure signals below the standard quantum limit.[23] Squeezed light has also been used to detect signals below the standard quantum limit in plasmonic sensors and atomic force microscopy.[24]

Uses of projection noise removal

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.[25][26] The diminishing projection noise has direct applications in communication protocols and nano-Nuclear Magnetic Resonance.[27][28]

Other uses of entanglement

Entanglement can be used to improve upon existing atomic clocks[29][30][31] or create more sensitive magnetometers.[32][33]

Quantum radars

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.[34] A proof-of-concept quantum radar or quantum illuminator using quantum entangled microwaves was able to detect low reflectivity objects at room-temperature – such may be useful for improved radar systems, security scanners and medical imaging systems.[35][36][37]

Neuroimaging

In neuroimaging, the first quantum brain scanner uses magnetic imaging and could become a novel whole-brain scanning approach.[38][39]

Gravity cartography of subterraneans

Quantum gravity-gradiometers that could be used to map and investigate subterraneans are also in development.[40][41]


References

  1. ^
    S2CID 118404862
    .
  2. S2CID 219124060
    .
  3. ^
    S2CID 53626745
    .
  4. ^
    S2CID 2555443
    .
  5. ^
    S2CID 15318256
    .
  6. ^
    doi:10.1016/j.pquantelec.2023.100497
    .
  7. S2CID 26890855
    .
  8. S2CID 2396896
    .
  9. S2CID 6470118
    .
  10. S2CID 109058131
    .
  11. S2CID 244799128
    .
  12. S2CID 119008607
    .
  13. S2CID 26952809
    .
  14. S2CID 119250709
    .
  15. S2CID 1398387
    .
  16. PMID 24679294
    .
  17. ^ DARPA Quantum Sensor Program.
  18. ^ BROAD AGENCY ANNOUNCEMENT (BAA) 07-22 Quantum Sensors
  19. S2CID 54955615
    .
  20. ^ Kelley M. Sayler (June 7, 2021). Defense Primer: Quantum Technology (PDF) (Report). Congressional Research Service. Retrieved July 22, 2021.
  21. S2CID 119001470
    .
  22. S2CID 28876707
    .
  23. S2CID 211031944
    .
  24. S2CID 118422029
    .
  25. S2CID 25870660
    .
  26. S2CID 32680254
    .
  27. S2CID 136428582
    .
  28. S2CID 172297
    .
  29. PMID 9914139
    .
  30. S2CID 245837971
    .
  31. S2CID 257632503
    .
  32. S2CID 31287682
    .
  33. S2CID 33820154
    .
  34. S2CID 27569963
    .
  35. ^ "Scientists demonstrate quantum radar prototype". phys.org. Retrieved June 12, 2020.
  36. ^ ""Quantum radar" uses entangled photons to detect objects". New Atlas. May 12, 2020. Retrieved June 12, 2020.
  37. PMID 32548249
    .
  38. ^ "Researchers build first modular quantum brain sensor, record signal". phys.org. Retrieved July 11, 2021.
  39. arXiv:2106.05877 [physics.atom-ph
    ].
  40. PMID 35197616
    .
  41. ^ "Quantum Gravity Sensor Breakthrough Paves Way for Groundbreaking Map of World Under Earth's Surface". SciTechDaily. February 27, 2022. Retrieved March 2, 2022.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Quantum_sensor&oldid=1213171778"