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April 2019: Hidden order in quantum many-body dynamics of driven-dissipative nonlinear photonic lattices

Hidden Order in Quantum Many-body Dynamics of Driven-Dissipative Nonlinear Photonic Lattices
J. Tangpanitanon, S. R. Clark, V. M. Bastidas, R. Fazio, D. Jaksch, D. G. Angelakis
Phys. Rev. A. 99, 033618 (2019) [PDF]

 

We study the dynamics of nonlinear photonic lattices driven by two-photon parametric processes. By means of matrix-product-state–based calculations, we show that a quantum many-body state with long-range hidden order can be generated from the vacuum. Although this order resembles that characterizing the Haldane insulator, our system is far from equilibrium due to the drive and photon loss. A possible explanation highlighting the role of the symmetry of the drive and the effect of photon loss is discussed. An implementation based on superconducting circuits is proposed and analyzed.


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March 2019: Two new works out! One on detecting topological order in quantum many-body systems in Phys. Rev. B and one in probing many-body localization in open photonic systems published in Phys. Rev. A

Strongly correlated photon transport in a nonlinear photonic lattice with the disorder: Probing signatures of the localization transition
T. F. See, V. M. Bastidas, J. Tangpanitanon, D. G. Angelakis
Phys. Rev. A. 99, 033835 (2019) [PDF]

We study the transport of few-photon states in open disordered nonlinear photonic lattices. More specifically, we consider a waveguide quantum electrodynamics (QED) setup where photons are scattered from a chain of nonlinear resonators with on-site Bose-Hubbard interaction in the presence of an incommensurate potential. Applying our recently developed diagrammatic technique that evaluates the scattering matrix (S matrix) via absorption and emission diagrams, we compute the two-photon transmission probability and show that it carries signatures of the underlying localization transition of the system. We compare the calculated probability to the participation ratio of the eigenstates and find close agreement for a range of interaction strengths. The scaling of the two-photon transmission probability suggests that there might be two localization transitions in the high energy eigenstates corresponding to interaction and quasiperiodicity respectively. This observation is absent from the participation ratio. We analyze the robustness of the transmission signatures against local dissipation and briefly discuss possible implementation using current technology.

Detection of topological phases by quasilocal operators
W. C. Yu, P.D. Sacramento, Y. Chao, D. G. Angelakis, Hai-Qing Lin
Phys. Rev. B 99, 115113 (2019) [PDF]

It was proposed recently by some of the authors that the quantum phase transition of a topological insulator like the Su-Schrieffer-Heeger (SSH) model may be detected by the eigenvalues and eigenvectors of the reduced density matrix. Here we further extend the scheme of identifying the order parameters by considering the SSH model with the addition of triplet superconductivity. This model has a rich phase diagram due to the competition of the SSH “order” and the Kitaev “order,” which requires the introduction of four order parameters to describe the various topological phases. We show how these order parameters can be expressed simply as averages of projection operators on the ground state at certain points deep in each phase and how one can simply obtain the phase boundaries. A scaling analysis in the vicinity of the transition lines is consistent with the quantum Ising universality class.

 

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September 2018 “Discrete time crystal in globally driven interacting quantum systems without disorder” (March 2019, published!)

Fig.1 (a) Schematic diagram showing the dynamics of the individual spins in our model for a small perturbation  in the spin flip. The presence of interaction helps to synchronize the spins.

Authors

W. C. Yu, J. Tangpanitanon, A. W. Glaetzle, D. Jaksch, D. G. Angelakis

Abstract

Time crystals in periodically driven systems have initially been studied assuming either the ability to quench the Hamiltonian between different many-body regimes, the presence of disorder or long-range interactions. Here we propose a scheme to observe discrete time crystal dynamics in a one-dimensional driven quantum system of the Ising type with short-range interactions and no disorder. The system is subject only to a periodic kick by a global magnetic field, and no extra Hamiltonian quenching is performed.

Phys. Rev. A. 99, 033618 (2019) [PDF] 

Fig.1 (a) Schematic diagram showing the dynamics of the individual spins in our model for a small perturbation  in the spin flip. The presence of interaction helps to synchronize the spins.

Fig. 2(a) Color map of the Fourier spectrum of the stroboscopic magnetization in x direction with perturbation \epsilon as the driving parameter.

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Dec 2017-publication in Science: Spectroscopic signatures of localization with interacting photons in superconducting qubits (collaboration with Google-Martinis group)

The international team used photons in Google’s quantum chip to simulate the surprising and beautiful pattern of the ‘Hofstadter butterfly’, a fractal structure characterizing the behaviour of electrons in strong magnetic fields. The results, published 1 December in Science, show how quantum simulators are starting to live up to their promise as powerful tools,…
Read more from CQT highlight for non specialists  ” CQT researchers collaborate in quantum simulations on Google’s superconducting chip” and from USBC highlight ” Simulating physics “

 

This work is highlighted in 12 science news including Strait Time phys.orgeurekalertsciencedailytech2.orghousseniawritingtuc.gr , asian scientist, technology networks, nanowerk, alphagalileo, mgronline 

Science 358, 6367, pp. 1175-1179 (2017)

Authors

P. Roushan, C. Neill, J. Tangpanitanon, V.M. Bastidas, A. Megrant, R. Barends, Y. Chen, Z. Chen, B. Chiaro, A. Dunsworth, A. Fowler, B. Foxen, E. Je rey, J. Kelly, E. Lucero, J. Mutus, M. Neeley, C. Quintana, D. Sank, A. Vainsencher, J. Wenner, T. White, H. Neven, D. G. Angelakis, and J. Martinis

Abstracts

Quantized eigenenergies and their associated wave functions provide extensive information for predicting the physics of quantum many-body systems. Using a chain of nine superconducting qubits, we implement a technique for resolving the energy levels of interacting photons. We benchmark this method by capturing the main features of the intricate energy spectrum predicted for two-dimensional electrons in a magnetic field—the Hofstadter butterfly. We introduce disorder to study the statistics of the energy levels of the system as it undergoes the transition from a thermalized to a localized phase. Our work introduces a many-body spectroscopy technique to study quantum phases of matter.

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November 2017: Realizing topological relativistic dynamics with slow light polaritons at room temperature

Authors

M. Namazi, B. Jordaan, C. Noh, D. G. Angelakis, E. Figueroa

Abstract

Here we use a slow light quantum light-matter interface at room temperature to implement an analog simulator of complex relativistic and topological physics. We have realized the famous Jackiw-Rebbi model (JR), the celebrated first example where relativity meets topology. Our system is based upon interacting dark state polaritons (DSP’s) created by storing light in a rubidium vapor using a dual-tripod atomic system. The DSP’s temporal evolution emulates the physics of Dirac spinors and is engineered to follow the JR regime by using a linear magnetic field gradient. We also probe the obtained topologically protected zero-energy mode by analyzing the time correlations between the spinor components. Our implementation paves the way towards quantum simulation of more complex phenomena involving many quantum relativistic particles.

arxiv.org/1711.09346