Conformal invariance and quantum non-locality in critical hybrid circuits

Kavli Affiliate: Matthew P. A. Fisher | First 5 Authors: Yaodong Li, Xiao Chen, Andreas W. W. Ludwig, Matthew P. A. Fisher, | Summary: We establish the emergence of a conformal field theory (CFT) in a (1+1)-dimensional hybrid quantum circuit right at the measurement-driven entanglement transition by revealing space-time conformal covariance of entanglement entropies and […]


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Hamiltonian deformations in quantum mechanics, $Tbar T$, and SYK

Kavli Affiliate: David J. Gross | First 5 Authors: David J. Gross, Jorrit Kruthoff, Andrew Rolph, Edgar Shaghoulian, | Summary: Motivated by $Tbar T$, we introduce and study a wide class of solvable deformations of quantum-mechanical theories. These deformations map the Hamiltonian to a function of itself. We solve these theories by computing all finite-temperature […]


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$Toverline{T}$ in AdS$_2$ and Quantum Mechanics

Kavli Affiliate: David J. Gross | First 5 Authors: David J. Gross, Jorrit Kruthoff, Andrew Rolph, Edgar Shaghoulian, | Summary: Quantum field theory in zero spatial dimensions has a rich infrared landscape and a universal ultraviolet, inverting the usual Wilsonian paradigm. For holographic theories this implies a rich landscape of asymptotically AdS$_2$ geometries. Isolating the […]


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Diffraction limited centimeter scale radiator: metasurface grating antenna for phased array LiDAR

Kavli Affiliate: Larry Coldren | Summary:In this paper, we demonstrate a radiation-strength-chirped metasurface centimeter-long grating antenna, whose beam quality is approaching the diffraction limit in its footprint with 90 percent efficiency.Instead of chirping the duty cycle to tune radiation strength, which calls for non-scalable fabrication resolution, we design a 2D fish-bone surface grating with apodized […]


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Efficient and accurate modeling of multi-wavelength propagation in SOAs: a generalized coupled-mode approach

Kavli Affiliate: Larry Coldren | Summary:We present a model for multi-wavelength mixing in semiconductor optical amplifiers (SOAs) based on coupled-mode equations. The proposed model applies to all kinds of SOA structures, takes into account the longitudinal dependence of carrier density caused by saturation, it accommodates an arbitrary functional dependencies of the material gain and carrier […]


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Quantum dot nonlinearity through cavity-enhanced feedback with a charge memory

Kavli Affiliate: Larry Coldren | Summary:In an oxide apertured quantum dot (QD) micropillar cavity-QED system, we found strong QD hysteresis effects and lineshape modifications even at very low intensities corresponding to less than 0.001 intracavity photons. We attribute this to the excitation of charges by the intracavity field; charges that get trapped at the oxide […]


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Polarization degenerate solid-state cavity QED

Kavli Affiliate: Larry Coldren | Summary:A polarization degenerate microcavity containing charge-controlled quantum dots (QDs) enables equal coupling of all polarization degrees of freedom of light to the cavity QED system, which we explore through resonant laser spectroscopy. We first measure interference of the two fine-split neutral QD transitions and find very good agreement of this […]


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Polarization degenerate micropillars fabricated by designing elliptical oxide apertures

Kavli Affiliate: Larry Coldren | Summary:A method for fabrication of polarization degenerate oxide apertured micropillar cavities is demon- strated. Micropillars are etched such that the size and shape of the oxide front is controlled. The polarization splitting in the circular micropillar cavities due to the native and strain induced bire- fringence can be compensated by […]


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