Astronomical random numbers for quantum foundations experiments

Abstract

Photons from distant astronomical sources can be used as a classical source of randomness to improve fundamental tests of quantum nonlocality, wave-particle duality, and local realism through Bell's inequality and delayed-choice quantum eraser tests inspired by Wheeler's cosmic-scale Mach-Zehnder interferometer gedankenexperiment. Such sources of random numbers may also be useful for information-theoretic applications such as key distribution for quantum cryptography. Building on the design of an "astronomical random-number generator" developed for the recent "cosmic Bell" experiment [Handsteiner et al., Phys. Rev. Lett. 118, 060401 (2017)], in this paper we report on the design and characterization of a device that, with 20-nanosecond latency, outputs a bit based on whether the wavelength of an incoming photon is greater than or less than 700 nm. Using the one-meter telescope at the Jet Propulsion Laboratory (JPL) Table Mountain Observatory, we generated random bits from astronomical photons in both color channels from 50 stars of varying color and magnitude, and from 12 quasars with redshifts up to $z=3.9$. With stars, we achieved bit rates of $\sim 1\times 10^6$ Hz / m${}^2$, limited by saturation for our single-photon detectors, and with quasars of magnitudes between 12.9 and 16, we achieved rates between $\sim 10^2$ and $2\times 10^3$ Hz /m${}^2$. For bright quasars, the resulting bitstreams exhibit sufficiently low amounts of statistical predictability as quantified by the mutual information. In addition, a sufficiently high fraction of bits generated are of true astronomical origin in order to address both the locality and freedom-of-choice loopholes when used to set the measurement settings in a test of the Bell-CHSH inequality.

17 pages, 12 figures. References added and minor edits to match published version

References in corpus (14)

• Satellite-relayed intercontinental quantum network
• Device-independent quantum key distribution secure against collective attacks
• Event-Ready Bell Test Using Entangled Atoms Simultaneously Closing Detection and Locality Loopholes
• Loopholes in Bell Inequality Tests of Local Realism
• Local deterministic model of singlet state correlations based on relaxing measurement independence
• Cosmic Bell Test: Measurement Settings from Milky Way Stars
• Frequency-dependent effects of gravitational lensing within plasma
• Relaxed Bell inequalities and Kochen-Specker theorems
• Delayed-choice test of complementarity with single photons
• Reliable numerical key rates for quantum key distribution
• Quantum erasure with causally disconnected choice
• Bell Test Over Extremely High-Loss Channels: Towards Distributing Entangled Photon Pairs Between Earth and Moon
• Quantum key distribution protocol with pseudorandom bases
• Random number generation with cosmic photons

Cited by in corpus (10)

• Cosmic Bell Test using Random Measurement Settings from High-Redshift Quasars
• Rethinking Superdeterminism
• Testing Local Realism into the Past without Detection and Locality Loopholes
• Real-Time Source Independent Quantum Random Number Generator with Squeezed States
• Relaxed Bell Inequalities with Arbitrary Measurement Dependence for Each Observer
• A Toy Model for Local and Deterministic Wave-function Collapse
• Timelessness strictly inside the Quantum Realm
• Testing the Weak Equivalence Principle using Optical and Near-Infrared Crab Pulses
• Tackling Loopholes in Experimental Tests of Bell's Inequality
• A Family of Local Deterministic Models for Singlet Quantum State Correlations