Research Project: Dielektik Dalga Kılavuzu - Yüzey Plazmon Josephon Eklemlerinin Fiziği ve Uygulamaları: Klasikten Kuantum Plazmoniğine
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Contributors
Funders
ID
TB.00079
Authors
Güven, Kaan
Faculty Member
Publications
Asymmetric Rosen-Zener-like transition through a soliton-surface-plasmon photonic Josephson junction with spatially varying coupling
(American Physical Society (APS), 2017) Aydındoğan, Güneş; Güven, Kaan; Department of Physics; Yes; College of Sciences
The transition dynamics of photons between an optical soliton in a nonlinear dielectric waveguide and a spatially coupled surface-plasmon excitation on a parallel flat metal surface can be formulated in analogy to that of a Josephson junction of two-level (double-well) Bose-Einstein condensates, albeit with a nonlinear coupling that inherently depends on the population imbalance of the levels. The present work demonstrates that asymmetric Rosen-Zener-like transitions can be obtained through this optical Josephson junction, by turning on and off the coupling across a hyperbolically varying separation between the soliton and the surface-plasmon. The transitions can generate full population transfer, population splitting, or merging between the quasistationary initial and final states, which are defined by a fixed population imbalance in the decoupled limit. Transitions from a pure soliton or pure surface-plasmon initial state are found to be robust against the relative phase, whereas the transitions from an initial state with mixed population depend strongly on the relative phase. The soliton-surface-plasmon system also bears similarities to the spatially coupled optical waveguides which are introduced further as the classical analogs of the spatial adiabatic passage and stimulated Raman adiabatic passage mechanisms in quantum and atom optics.
Two-frequency Jahn-Teller systems in circuit QED
(American Physical Society (APS), 2012) Gül, Yusuf; Müstecaplıoğlu, Özgür Esat; Dereli, Tekin; Forn-Diaz, Pol; Department of Physics; Yes; College of Sciences
We investigate the simulation of Jahn-Teller models with two nondegenerate vibrational modes using a circuit QED architecture. Typical Jahn-Teller systems are anisotropic and require at least a two-frequency description. The proposed simulator consists of two superconducting lumped-element resonators interacting with a common flux qubit in the ultrastrong coupling regime. We translate the circuit QED model of the system to a two-frequency Jahn-Teller Hamiltonian and calculate its energy eigenvalues and the emission spectrum of the cavities. It is shown that the system can be systematically tuned to an effective single-mode Hamiltonian from the two-mode model by varying the coupling strength between the resonators. The flexibility in manipulating the parameters of the circuit QED simulator permits the isolation of the effective single-frequency and pure two-frequency effects in the spectral response of Jahn-Teller systems.
Transfer of spin squeezing and particle entanglement between atoms and photons in coupled cavities via two-photon exchange
(Optical Society of America (OSA), 2012) Hardal, Ali Ümit Cemal; Müstecaplıoğlu, Özgür Esat; Department of Physics; Graduate School of Sciences and Engineering; Yes; College of Sciences; GRADUATE SCHOOL OF SCIENCES AND ENGINEERING
We examine transfer of particle entanglement and spin squeezing between atomic and photonic subsystems in optical cavities coupled by two-photon exchange. Each cavity contains a single atom, interacting with cavity photons with a two-photon cascade transition. Particle entanglement is characterized by evaluating optimal spin squeezing inequalities for the cases of initially separable and entangled two-photon states. It is found that particle entanglement is first generated among the photons in separate cavities and then transferred to the atoms. The underlying mechanism is recognized as an intercavity two-axis twisting spin squeezing interaction, induced by two-photon exchange, and its optimal combination with the intracavity atom-photon coupling. Relative effect of nonlocal two-photon exchange and local atom-photon interactions of cavity photons on the spin squeezing and entanglement transfer is pointed out.
Spin squeezing, entanglement, and coherence in two driven, dissipative, nonlinear cavities coupled with single- and two-photon exchange
(Optical Society of America (OSA), 2014) Hardal, Ali Ümit Cemal; Müstecaplıoğlu, Özgür Esat; Department of Physics; Yes; College of Sciences
We investigate spin squeezing, quantum entanglement, and second-order coherence in two coupled, driven, dissipative, nonlinear cavities. We compare these quantum statistical properties for the cavities coupled with either single- or two-photon exchange. Solving the quantum optical master equation of the system numerically in the steady state, we calculate the zero-time delay second-order correlation function for the coherent, genuine two-mode entanglement parameters, an optimal spin squeezing inequality associated with particle entanglement, concurrence, quantum entropy, and logarithmic negativity. We identify regimes of distinct quantum statistical character depending on the relative strength of photon exchange and nonlinearity. Moreover, we examine the effects of weak and strong drives on these quantum statistical regimes.
Dissipative Josephson junction of an optical soliton and a surface plasmon
(American Physical Society (APS), 2013) Güven, Kaan; Müstecaplıoğlu, Özgür Esat; Özok, Yasa Ekşioğlu; Department of Physics; Yes; College of Sciences
We examine the dynamics of a dissipative photonic Josephson junction formed by the weak coupling of an optical soliton in a nonlinear dielectric waveguide and a co-propagating surface plasmon along a parallel metal surface with a linear dielectric spacer. We employ a heuristic model with a coupling function that depends on the soliton amplitude and consider two phenomenological dissipation mechanisms separately: angular-velocity dissipation and population imbalance dissipation. In the former dissipation mechanism, the system exhibits a phase-slip phenomenon where the odd-pi phase modes decay into even-pi phase modes. The latter damping mechanism sculptures the phase space significantly by introducing complex features, among which, Hopf-type bifurcations are notable. We show that some of the bifurcation points expand to stable limit cycles for certain regimes of the model parameters.
