Unidirectional quantum walk of two correlated particles: Manipulating bound-pair and unbound wave-packet components

Abstract

We study the unidirectional transport of two-particle quantum wavepackets in a regular onedimensional lattice. We show that the bound-pair state component behaves differently from unbound states when subjected to an external pulsed electric field. Thus, strongly entangled particles exhibit a quite distinct dynamics when compared to a single particle system. With respect to centroid motion, our numerical results are corroborated with an analytical expression obtained using a semiclassical approach. The wavefunction profile reveals that the particle-particle interaction induces the splitting of the initial wavepacket into two branches that propagate with specific directions and drift velocities. With a proper external field tunning, the wavepacket components can perform an unidirectional transport on the same or opposite directions. The amplitude of each mode is related to the degree of entanglement betweem particles, which presents a non-monotonic dependence on the interaction strength.

Aperiodic space-inhomogeneous quantum walks: Localization properties, energy spectra, and enhancement of entanglement

“…With different transport properties to its classical analog, quantum walks have been proven to be versatile and highly controllable platform to describe quantum systems [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18] and quantum algorithms [19][20][21][22][23][24]. Besides the presence in different branches of science such as ferromagnetic films [3], bacteria in biological systems [4], quantum dots [5] and photosynthetic systems [7], quantum walks have also been the central subject of a wide range of experimental studies, either using nuclear magnetic resonance [11,12], trapped atoms [13,14], linear optics [15,16] or integrated photonics circuits [17,18].…”

Quantum walks assisted by particle-number fluctuations

“…Quantum walks of interacting pairs can be used to determine if graphs are isomorphic [37]. Particle correlations can be exploited to change the directionality of quantum walks [38]. Quantum walks of interacting particles can be used to realize quantum Hash schemes [39].…”

“…Quantum walks of interacting particles can be used to realize quantum Hash schemes [39]. Two-body or multi-particle correlations have been shown to affect quantum walks of few-and many-particle systems in interesting ways [33,38,[40][41][42][43][44][45][46][47][48][49][50][51]. These studies consider particle correlations arising either as a consequence of direct density -density interactions or particle quantum statistics.…”