Engineering and manipulating exciton wave packets

Zang, Xiaoning; Montangero, Simone; Carr, Lincoln D.; Lusk, Mark T.

doi:10.1103/physrevb.95.195423

Cited by 12 publications

(16 citation statements)

References 72 publications

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“…The next steps of many-body quantum simulation of robust Mott atomtronics switches, particularly their applications in strongly-correlated regimes, would address problems of materials science or other disciplines more directly, even in combination with open quantum systems for improved source and drain implementation. We could also look toward ultracold molecules for additional degrees of freedom, where the transport is of a spin rather than a mass [23,41]. Then we get a "moleculetronics" switch which is in fact spintronics in the ultracold context.…”

Section: Discussionmentioning

confidence: 99%

Quantum phase transition modulation in an atomtronic Mott switch

McLain¹,

Carr²

2018

Quantum Sci. Technol.

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Mott insulators provide stable quantum states and long coherence times due to small number fluctuations, making them good candidates for quantum memory and atomic circuits. We propose a proof-of-principle for a 1D Mott switch using an ultracold Bose gas and optical lattice. With time-evolving block decimation simulations -efficient matrix product state methods -we design a means for transient parameter characterization via a local excitation for ease of engineering into more complex atomtronics. We perform the switch operation by tuning the intensity of the optical lattice, and thus the interaction strength through a conductance transition due to the confined modifications of the "wedding cake" Mott structure. We demonstrate the time-dependence of Fock state transmission and fidelity of the excitation as a means of tuning up the device in a double well and as a measure of noise performance. Two-point correlations via the g (2) measure provide additional information regarding superfluid fragments on the Mott insulating background due to the confinement of the potential. arXiv:1804.03804v2 [cond-mat.quant-gas]

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Section: Discussionmentioning

confidence: 99%

Quantum phase transition modulation in an atomtronic Mott switch

McLain¹,

Carr²

2018

Quantum Sci. Technol.

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“…Lindblad equations without conserved quantities and local channels have a variety of applications reaching from the quantum Ising model with local spin flips over XXZ model transport problems using local channels at both end of the chains [68] to lossy photon cavities. We choose to simulate the transport of an exciton with the initial condition and Hamiltonian based on reference [69,70]. Examples of the Lindblad operators for transport problems can be motivated from [71], which describes energy loss and dephasing noise in molecular structures.…”

Section: B Local Lindblad Operators Without Symmetry (Qt Mpdo and mentioning

confidence: 99%

“…Subsystem A contains L A sites; subsystem C spans L C sites. The initial exciton is defined via the relation from [70] on the subsystem B with a size of L B sites:…”

Section: B Local Lindblad Operators Without Symmetry (Qt Mpdo and mentioning

confidence: 99%

One-dimensional many-body entangled open quantum systems with tensor network methods

Jaschke¹,

Montangero²,

Carr³

2018

Quantum Sci. Technol.

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We present a collection of methods to simulate entangled dynamics of open quantum systems governed by the Lindblad master equation with tensor network methods. Tensor network methods using matrix product states have been proven very useful to simulate many-body quantum systems and have driven many innovations in research. Since the matrix product state design is tailored for closed one-dimensional systems governed by the Schrödinger equation, the next step for many-body quantum dynamics is the simulation of one-dimensional open quantum systems. We review the three dominant approaches to the simulation of open quantum systems via the Lindblad master equation: quantum trajectories, matrix product density operators, and locally purified tensor networks. Selected examples guide possible applications of the methods and serve moreover as a benchmark between the techniques. These examples include the finite temperature states of the transverse quantum Ising model, the dynamics of an exciton traveling under the influence of spontaneous emission and dephasing, and a double-well potential simulated with the Bose-Hubbard model including dephasing. We analyze which approach is favorable leading to the conclusion that a complete set of all three methods is most beneficial, pushing the limits of different scenarios. The convergence studies using analytical results for macroscopic variables and exact diagonalization methods as comparison, show, for example, that matrix product density operators are favorable for the exciton problem in our study. All three methods access the same library, i.e., the software package Open Source Matrix Product States, allowing us to have a meaningful comparison between the different approaches based on the selected examples. For example, tensor operations are accessed from the same subroutines and with the same optimization eliminating one possible bias in a comparison of such numerical methods. CONTENTS

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“…This technical progress makes it possible to employ excitons to efficiently process and manipulate information encoded in light by bridging the gap between photonics and electronics 56 . An exciton that is generated by illuminating a molecule with C N (N ≥ 3) symmetry by twisted light, for example, obtains the AM of the absorbed photon, and it turns out that a chain of such molecules can be used to create excitonic wave packets with well defined linear and angular momenta 35,36,57 . A succession of absorption events generates excitonic wave packets carrying a range of AM.…”

Section: Introductionmentioning

confidence: 99%

First-principles methodology for determining the angular momentum of excitons

Zang

Schwingenschlögl

2019

Phys. Rev. B

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We develop a methodology for extracting the Kohn-Sham angular momentum of excitons in realistic systems from time-dependent density functional theory. For small systems the exciton populations can be calculated analytically, which allows us to test the methodology for a 3-arm H 2 molecular ring and a pair of such rings. For larger systems the developed methodology opens for the first time a venue to determine the angular momentum of excitons by first principles calculations. A chain of twenty 3-arm H 2 molecular rings and a triphenylphosphine molecule are investigated as illustrative examples. It is demonstrated that the angular momentum is conserved during the absorption of twisted light.

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Engineering and manipulating exciton wave packets

Cited by 12 publications

References 72 publications

Quantum phase transition modulation in an atomtronic Mott switch

Quantum phase transition modulation in an atomtronic Mott switch

One-dimensional many-body entangled open quantum systems with tensor network methods

First-principles methodology for determining the angular momentum of excitons

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