Quantum transport of energy in controlled synthetic quantum magnets

Abstract

We introduce a theoretical scheme that exploits laser cooling and phonon-mediated spin-spin interactions in crystals of trapped atomic ions to explore the transport of energy through a quantum magnet. We show how to implement an effective transport window to control the flow of energy through the magnet even in the absence of fermionic statistics for the carriers. This is achieved by shaping the density of states of the effective thermal reservoirs that arise from the interaction with the external bath of the modes of the electromagnetic field, and can be experimentally controlled by tuning the laser frequencies and intensities appropriately. The interplay of this transport window with the spin-spin interactions is exploited to build an analogue of the Coulomb-blockade effect in nano-scale electronic devices, and opens new possibilities to study quantum effects in energy transport.

Phonon-mediated repulsion, sharp transitions and (quasi)self-trapping in the extended Peierls-Hubbard model

“…This is critical for understanding quantum transport of interacting excitons in devices based on organic semiconductors (such as low-temperature solar cells) 28 , 29 and the prospects of observing the Mott-insulator/Peierls-insulator competition with highly controllable ultracold atoms/molecules systems, which require understanding of emergent interactions in the few-particle limit. The extended Peierls-Hubbard model can be realized for hard-core bosons with ions in rf-traps 30 – 33 , Rydberg atoms exchanging excitations 34 – 38 , self-assembled ultracold dipolar crystals 39 – 41 , arrays of polar molecules trapped in optical lattices 42 , 43 , arrays of superconducting qubits 44 – 49 , and J-aggregates 50 . Similar physics may also arise in the context of interacting impurities in a Fermi degenerate gas 51 – 53 or Bose-Einstein condensates 54 – 59 of ultracold atoms.…”

Trapped Ion Architecture for Multi‐Dimensional Quantum Simulations

“…iii) Quantum dynamics in crystalline or even non-periodic micro arrays might also permit studying complex transport and thermalisation processes. For example, featured by quantum walks, [16,17,[89][90][91] transport phenomena, [92][93][94][95][96] their expiration due to many-body localization [97] and equilibration/thermalization in 2D in open/closed quantum systems. [98][99][100][101] In addition, dependent on the density of the ensemble, it may be necessary to include boundary electrode structures to compensate for the overall Coulomb repulsion, [61] that is, mimicking infinite lattices.…”

Continuously parametrized quantum simulation of molecular electron transfer reactions

“…The versatility of trappedion arrays renders them ideal candidates to study elementary quantum transport processes under controlled conditions. Previous studies have focused on the transport of electronic (effective spins) and vibrational excitations (phonons) across ion chains [28][29][30][31], and on the influence of spin-phonon couplings on coherent exciton transport processes [32].…”