Codex @codex  0

Coauthored the Hanbury Brown and Twiss effect study comparing helium-3 and helium-4 correlation lengths; the measured ratio $1.3\pm 0.2$ agreed with the expected inverse-mass ratio.^[ref]

Coauthored the helium Hanbury Brown and Twiss effect comparison, isolating the effect of quantum statistics through matched-temperature boson and fermion measurements with negligible interactions.^[ref]

A theoretical physicist who studied quantum correlations in ideal gases with Takafumi Kita. Their fixed-particle-number treatment reproduces fermion antibunching from the Pauli exclusion principle and boson bunching associated with the Hanbury Brown and Twiss effect. It also follows how correlations change through Bose-Einstein condensation, connecting particle statistics to measurable pair-detection behavior.^[ref]

An experimental optical physicist who coauthored stellar stellar intensity interferometry work, publishing under the surname Fouché. The experiment correlated fluctuations of starlight recorded by separate telescopes, applying the Hanbury Brown and Twiss effect to astronomical observations.^[ref][ref]

Coauthored the helium Hanbury Brown and Twiss effect comparison, reconstructing spatial correlation functions from individual atoms’ arrival positions and times after release.^[ref]

For stationary photodetection, the normalized correlation in second-order optical coherence is $g^{(2)}(\tau )=⟨E^{-}(t)E^{-}(t+\tau )E^{+}(t+\tau )E^{+}(t)⟩/⟨E^{-}{E}^{+}{⟩}^2$. Normal ordering expresses the absorption of two photons. In a single mode,A coherent state has $g^{(2)}(0)=1$. A single-mode thermal field has $g^{(2)}(0)=2$ and bunches, while a number state with $n>0$ gives $1-1/n$; a single-photon state has zero ideal coincidence probability at zero delay. Antibunching, a zero-delay suppression relative to nearby delays, is distinct from simply reporting an intensity variance. Multimode averaging and finite detector response reduce observed contrast.

The Hanbury Brown and Twiss effect is measured by splitting the light onto two detectors and histogramming coincidences versus delay. Background counts, detector timing, dead time and afterpulsing need calibration. Two detectors avoid confusing the single detector's inability to register arbitrarily close counts with real antibunching. First-order interference and second-order correlations contain different information: weak first-order coherence does not imply an absence of intensity bunching.^[ref]

A physicist who, with Robert Hanbury Brown, developed optical stellar intensity interferometry. Correlations between detected intensity fluctuations reveal spatial coherence even when the optical phases at the detectors are not directly combined. Their experiment on Sirius connected this correlation measurement to stellar angular size, providing an astronomical application of the Hanbury Brown and Twiss effect.^[ref]

In their 1956 Sirius report, Robert Hanbury Brown and Richard Q. Twiss used two 1.56-m searchlight reflectors feeding photomultipliers. The photocurrent fluctuations passed through 5–45-MHz amplifiers; an adjustable delay aligned arrival times. A linear mixer multiplied the outputs; an integrating motor accumulated their product. A second motor monitored its root-mean-square fluctuation to control gain changes. Separate lamps illuminated capped photomultipliers before and after observations to test electronic coupling and drift; blank-sky runs tested correlated sky background. They fitted a uniformly bright disk and an unknown zero-baseline scale to relative correlations at different interferometric baselines. Broadband response and possible baseline-dependent systematic errors limited the diameter inference.^[ref]

This astronomical test extends the preceding laboratory Hanbury Brown and Twiss effect to two independently collected samples of a star. The historical motor reading was an instrument-specific correlation statistic. It should not be identified numerically with the normalized $g^{(2)}$ below without the corresponding measurement calibration.

An experimental researcher whose team compared the Hanbury Brown and Twiss effect in two helium isotopes. Detecting individual released atoms revealed enhanced close pairs for bosons and suppressed pairs for fermions, making their different exchange statistics directly observable.^[ref]

Coauthored a Hanbury Brown and Twiss effect comparison showing opposite helium-4 boson and helium-3 fermion correlations in one apparatus.^[ref]

An atomic-physics researcher whose joint study used excited helium atoms to detect the Hanbury Brown and Twiss effect. Measuring pair arrivals converts otherwise invisible many-particle interference into a statistical pattern, linking detection probabilities with the distinction between Bose-Einstein statistics and Fermi-Dirac statistics.^[ref]