Interplay of exchange and superexchange in triple quantum dots

• URL: http://arxiv.org/abs/2003.03416v1
• Date: Fri, 6 Mar 2020 20:11:16 GMT
• Title: Interplay of exchange and superexchange in triple quantum dots
• Authors: Kuangyin Deng, Edwin Barnes
• Abstract summary: Recent experiments on semiconductor quantum dots have demonstrated the ability to utilize a large quantum dot to mediate superexchange interactions. We show that superexchange processes strongly enhance and increase the range of the net spin-spin exchange as the dots approach a linear configuration. Our results can be used as a guide to assist further experimental efforts towards scaling up to larger, two-dimensional quantum dot arrays.
• Score: 0.0
• License: http://arxiv.org/licenses/nonexclusive-distrib/1.0/
• Abstract: Recent experiments on semiconductor quantum dots have demonstrated the ability to utilize a large quantum dot to mediate superexchange interactions and generate entanglement between distant spins. This opens up a possible mechanism for selectively coupling pairs of remote spins in a larger network of quantum dots. Taking advantage of this opportunity requires a deeper understanding of how to control superexchange interactions in these systems. Here, we consider a triple-dot system arranged in linear and triangular geometries. We use configuration interaction calculations to investigate the interplay of superexchange and nearest-neighbor exchange interactions as the location, detuning, and electron number of the mediating dot are varied. We show that superexchange processes strongly enhance and increase the range of the net spin-spin exchange as the dots approach a linear configuration. Furthermore, we show that the strength of the exchange interaction depends sensitively on the number of electrons in the mediator. Our results can be used as a guide to assist further experimental efforts towards scaling up to larger, two-dimensional quantum dot arrays.

Related papers

• Dipolar quantum solids emerging in a Hubbard quantum simulator [45.82143101967126]
  Long-range and anisotropic interactions promote rich spatial structure in quantum mechanical many-body systems. We show that novel strongly correlated quantum phases can be realized using long-range dipolar interaction in optical lattices. This work opens the door to quantum simulations of a wide range of lattice models with long-range and anisotropic interactions.
  arXiv  Detail & Related papers  (2023-06-01T16:49:20Z)
• Bound state of distant photons in waveguide quantum electrodynamics [137.6408511310322]
  Quantum correlations between distant particles remain enigmatic since the birth of quantum mechanics. We predict a novel kind of bound quantum state in the simplest one-dimensional setup of two interacting particles in a box. Such states could be realized in the waveguide quantum electrodynamics platform.
  arXiv  Detail & Related papers  (2023-03-17T09:27:02Z)
• Variational waveguide QED simulators [58.720142291102135]
  Waveguide QED simulators are made by quantum emitters interacting with one-dimensional photonic band-gap materials. Here, we demonstrate how these interactions can be a resource to develop more efficient variational quantum algorithms.
  arXiv  Detail & Related papers  (2023-02-03T18:55:08Z)
• Tunable photon-mediated interactions between spin-1 systems [68.8204255655161]
  We show how to harness multi-level emitters with several optical transitions to engineer photon-mediated interactions between effective spin-1 systems. Our results expand the quantum simulation toolbox available in cavity QED and quantum nanophotonic setups.
  arXiv  Detail & Related papers  (2022-06-03T14:52:34Z)
• Sign-switching of superexchange mediated by few electrons under non-uniform magnetic field [7.33811357166334]
  Long range interaction between distant spins is an important building block for the realization of large quantum-dot network. Recent experiments on coherent logical states oscillation between remote spins facilitated by intermediate electron states has paved the first step for large scale quantum information processing. Our work can be a guide to scale up the quantum-dot array with controllable and dense connectivity.
  arXiv  Detail & Related papers  (2022-04-06T06:53:09Z)
• Tuning long-range fermion-mediated interactions in cold-atom quantum simulators [68.8204255655161]
  Engineering long-range interactions in cold-atom quantum simulators can lead to exotic quantum many-body behavior. Here, we propose several tuning knobs, accessible in current experimental platforms, that allow to further control the range and shape of the mediated interactions.
  arXiv  Detail & Related papers  (2022-03-31T13:32:12Z)
• Universal control of superexchange in linear triple quantum dots with an empty mediator [6.211541620389987]
  We study a two-electron system in a linear triple-quantum-dot device in which the left and right dots are occupied by a single electron each. Our results suggest that even a simple configuration of delocalized two-electron states in a linear triple-quantum-dot device exhibits superexchange energy with non-trivial behaviors.
  arXiv  Detail & Related papers  (2022-03-29T13:01:48Z)
• Dynamics of a multipartite hybrid quantum system with beamsplitter, dipole-dipole, and Ising interactions [0.0]
  We make use of one such hybrid bipartite quantum model, with one subsystem made of a pair of qubits and another comprising a pair of oscillators. Our basic model is the standard double Jaynes-Cummings system, which is known to support both entanglement transfer and entanglement sudden death. We show that compared to the beamsplitter or dipole-dipole interaction, the Ising interaction can have a significant positive impact on entanglement sudden death and birth.
  arXiv  Detail & Related papers  (2021-12-21T21:12:08Z)
• A quantum processor based on coherent transport of entangled atom arrays [44.62475518267084]
  We show a quantum processor with dynamic, nonlocal connectivity, in which entangled qubits are coherently transported in a highly parallel manner. We use this architecture to realize programmable generation of entangled graph states such as cluster states and a 7-qubit Steane code state.
  arXiv  Detail & Related papers  (2021-12-07T19:00:00Z)
• Quantum amplification of boson-mediated interactions [0.0]
  We experimentally demonstrate the amplification of a boson-mediated interaction between two trapped-ion qubits by parametric modulation of the trapping potential. The technique can be used in any quantum platform where parametric modulation of the boson channel is possible.
  arXiv  Detail & Related papers  (2020-09-29T23:22:55Z)
• Exchange coupling in a linear chain of three quantum-dot spin qubits in silicon [2.161915301690476]
  Quantum gates between spin qubits can be implemented leveraging the natural Heisenberg exchange interaction between two electrons in contact with each other. Superexchange is the coupling between remote spins mediated by a third idle electron that bridges the distance between quantum dots. We experimentally demonstrate direct exchange coupling and provide evidence for second neighbour mediated superexchange in a linear array of three single-electron spin qubits in silicon.
  arXiv  Detail & Related papers  (2020-04-16T14:01:51Z)

This list is automatically generated from the titles and abstracts of the papers in this site.

This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.