Ensemble-Averaged Quantum Correlations between Path-Entangled Photons Undergoing Anderson Localization

Abstract

We measure ensemble-averaged quantum correlations of path-entangled photons, propagating in a disordered lattice and undergoing Anderson localization. These result in intriguing patterns, which show that quantum interference leads to unexpected dependencies of the location of one particle on the location of the other. These correlations are shared between localized and nonlocalized components of the two-photon wave function, and, moreover, yield information regarding the nature of the disorder itself. Such effects cannot be reproduced with classical waves, and are undetectable without ensemble averaging.

Two-particle four-point correlations in dynamically disordered tight-binding networks

“…Yet, most investigations have solely considered second-order two-particle correlations in lattices that are affected by static disorder in either the site energies or the coupling coefficients [5][6][7]. Interestingly, little has been said about the impact of dynamic disorder on the evolution of two-particle correlations in such lattice systems.…”

“…In this regard, of particular interest has been the study of quantum correlations between indistinguishable particles co-propagating in time-independent disordered lattices [4][5][6][7].…”

Effects of long-range hopping and interactions on quantum walks in ordered and disordered lattices

“…This has stimulated the development of experiments to study quantum walks in lattice potentials. Quantum walks have been studied with photons in disordered media [4][5][6][7], ions in rf traps [8][9][10] and ultracold atoms in optical lattices [11][12][13][14]. The study of quantum walks in lattice potentials has potential to uncover novel features of quantum dynamics [15], as evidenced by an abundance of theoretical work on quantum walks under various conditions [16][17][18][19].…”

Hanbury Brown and Twiss anticorrelation in disordered photonic lattices

“…Indeed, by coupling a coherent input to a single lattice site, Anderson localization [12] has been observed in the transverse direction upon ensemble averaging [13][14][15][16]. Beyond the mean intensity observed in such experiments, unique features of the higher-order field correlations involved in the HBT effect have only recently been explored [17][18][19][20][21][22][23]. Indeed, HBT measurements can distinguish between the so-called 'diagonal' and 'off-diagonal' classes of lattice disorder, whereas such a delineation is not possible by observing the mean field alone [18].…”