Single photon randomness originating from the symmetric dipole emission pattern of quantum emitters

Abstract

Quantum random number generation is a key ingredient for quantum cryptography and fundamental quantum optics and could advance Monte Carlo simulations and machine learning. An established generation scheme is based on single photons impinging on a beam splitter. Here, we experimentally demonstrate quantum random number generation solely based on the symmetric emission profile of a dipole aligned orthogonal to the laboratory frame. The demonstration builds on defect centers in hexagonal boron nitride that emit photons in random directions within the dipole emission profile and benefits from the ability to manipulate and align the emission directionality. We prove the randomness in correlated photon detection events making use of the NIST randomness test suite and show that the randomness remains for two independently emitting defect centers. The scheme can be extended to random number generation by coherent single photons with potential applications in solid-state based quantum communication at room temperature.

Quantum Emitters in Hexagonal Boron Nitride

“…While key questions remain elusiveincluding the emitters’ atomic/​crystallographic structures and the ability to engineer stable emitters in monolayersmajor efforts are underway aiming to improve the reproducibility of emitter engineering and understanding of atomic and electronic structures. However, even in their current state, hBN emitters have been successfully utilized to realize technologically important quantum random generators , and employed in an extended quantum theory test . As discussed above, one of the reasons why hBN SPEs attracted such a broad attention is their ease of engineering.…”

Tailoring the Emission Wavelength of Color Centers in Hexagonal Boron Nitride for Quantum Applications

“…In addition, the robustness of the emitters, their long-term stability, and a fast radiative decay lifetime allowing high repetition rates [ 21 , 25 ], has led to the general understanding that these emitters can be used in practical quantum information processing applications. In fact, single photons emitted from hBN have been used for quantum random number generation [ 26 , 27 ] and single photon interferometry [ 28 ]. Their linewidth at room temperature, however, still needs substantial improvement in order to be used for optical quantum computing [ 29 ].…”

Coherent Quantum Emitters in Hexagonal Boron Nitride

“…Further examples of quantum optics applications include quantum random number generation, as reported with [ 118 ] and without [ 119 ] beamsplitter with high entropy per raw bit. Having coherent optical transitions at hand brings applications based on indistinguishable single photon emission into reach, including quantum repeater, distributed quantum computing and quantum networks as well as photonics assisted quantum‐metrology.…”