Single-photon-driven high-order sideband transitions in an ultrastrongly coupled circuit quantum electrodynamics system

We report the experimental observation of high-order sideband transitions at the single-photon level in a quantum circuit system of a flux qubit ultrastrongly coupled to a coplanar waveguide resonator. With the coupling strength reaching 10% of the resonator's fundamental frequency, we obtain clear signatures of higher-order red and first-order blue-sideband transitions, which are mainly due to the ultrastrong Rabi coupling. Our observation advances the understanding of ultrastrongly-coupled systems and paves the way to study high-order processes in the quantum Rabi model at the single-photon level.Comment: Accepted in Physical Review A. 12 pages, 6 figure

Long-lived Microwave Electromechanical Systems Enabled by Cubic Silicon-Carbide Membrane Crystals

Cubic silicon-carbide crystals, known for their high thermal conductivity and in-plane stress, hold significant promise for the development of high-quality ($Q$) mechanical oscillators. Enabling coherent electrical manipulation of long-lived mechanical resonators would be instrumental in advancing the development of phononic memories, repeaters, and transducers for microwave quantum states. In this study, we demonstrate the compatibility of high-stress and crystalline (3C-phase) silicon-carbide membranes with superconducting microwave circuits. We establish a coherent electromechanical interface for long-lived phonons, allowing precise control over the electromechanical cooperativity. This interface enables tunable slow-light time with group delays extending up to an impressive duration of \emph{an hour}. We then investigate a phononic memory based on the high-$Q$ ($10^{8}$) silicon-carbide membrane, capable of storing and retrieving microwave coherent states \emph{on-demand}. The thermal and coherent components can be distinguished through state tomography in quadrature phase space, which shows an exponential increase and decay trend respectively as the storage time increases. The electromechanical interface and phononic memory made from crystalline silicon-carbide membrane possess enticing attributes, including low microwave-induced mechanical heating, phase coherence, an energy decay time of $T_{1}=19.9$~s, and it acquires less than one quantum noise within $\tau_{\textrm{coh}}=41.3$~ms storage period. These findings underscore the unique opportunities provided by cubic silicon-carbide membrane crystals for the storage and transfer of quantum information across distinct components of hybrid quantum systems

Strong coupling between a single photon and a photon pair

The realization of strong nonlinear coupling between single photons has been a long-standing goal in quantum optics and quantum information science, promising wide impact applications, such as all-optical deterministic quantum logic and single-photon frequency conversion. Here, we report an experimental observation of the strong coupling between a single photon and a photon pair in an ultrastrongly-coupled circuit-QED system. This strong nonlinear interaction is realized by introducing a detuned flux qubit working as an effective coupler between two modes of a superconducting coplanar waveguide resonator. The ultrastrong light--matter interaction breaks the excitation number conservation, and an external flux bias breaks the parity conservation. The combined effect of the two enables the strong one--two-photon coupling. Quantum Rabi-like avoided crossing is resolved when tuning the two-photon resonance frequency of the first mode across the single-photon resonance frequency of the second mode. Within this new photonic regime, we observe the second harmonic generation for a mean photon number below one. Our results represent a key step towards a new regime of quantum nonlinear optics, where individual photons can deterministically and coherently interact with each other in the absence of any stimulating fields.Comment: 13 pages, 7 figure

Gate-Compatible Circuit QED in a Three-Dimensional Cavity Architecture

Semiconductor-based superconducting qubits offer a versatile platform for studying hybrid quantum devices in circuit quantum electrodynamics (cQED) architecture. Most of these cQED experiments utilize coplanar waveguides, where the incorporation of DC gate lines is straightforward. Here, we present a technique for probing gate-tunable hybrid devices using a three-dimensional (3D) microwave cavity. A recess is machined inside the cavity wall for the placement of devices and gate lines. We validate this design using a hybrid device based on an InAs-Al nanowire Josephson junction. The coupling between the device and the cavity is facilitated by a long superconducting strip, the antenna. The Josephson junction and the antenna together form a gatemon qubit. We further demonstrate the gate-tunable cavity shift and two-tone qubit spectroscopy. This technique could be used to probe various quantum devices and materials in a 3D cQED architecture that requires DC gate voltages

Preparation and Characterization of Montmorillonite Intercalation Compounds with Quaternary Ammonium Surfactant: Adsorption Effect of Zearalenone

Montmorillonite (Mt) was used as the original material to prepare intercalation compounds with quaternary ammonium surfactant (QAS). The adsorption of zearalenone (ZEA) onto Mt and organomodified Mt was investigated in vitro. Effects of QAS in binding ZEA were studied. By the method of intercalation with dioctadecylmethylbenzylammonium chloride (DOMBAC), the sample exhibited the highest adsorption rate of ZEA (93.2%) which was much higher than that of Mt (10.5%). Several methods were adopted to characterize samples, including XRD, TG/DSC, N2 adsorption/desorption, and FTIR. Adsorption isotherm parameters were obtained from Langmuir and Freundlich and the adsorption data fitted better to Langmuir. All results indicate that organomodified Mt has great potential to be a high-performance material to control ZEA contamination

Optomechanical Anti-Lasing with Infinite Group Delay at a Phase Singularity

Funding Information: This work is supported by the National Key Research and Development Program of China (Grant No. 2016YFA0301200), the National Natural Science Foundation of China (Grant No. 12004044, Grants No. 62074091 and No. U1930402), and Science Challenge Project (Grant No. TZ2018003), and by the Academy of Finland (Contracts No. 307757, No. 312057, No. 336810). Publisher Copyright: © 2021 American Physical Society.Singularities which symbolize abrupt changes and exhibit extraordinary behavior are of a broad interest. We experimentally study optomechanically induced singularities in a compound system consisting of a three-dimensional aluminum superconducting cavity and a metalized high-coherence silicon nitride membrane resonator. Mechanically induced coherent perfect absorption and anti-lasing occur simultaneously under a critical optomechanical coupling strength. Meanwhile, the phase around the cavity resonance undergoes an abrupt π-phase transition, which further flips the phase slope in the frequency dependence. The observed infinite discontinuity in the phase slope defines a singularity, at which the group velocity is dramatically changed. Around the singularity, an abrupt transition from an infinite group advance to delay is demonstrated by measuring a Gaussian-shaped waveform propagating. Our experiment may broaden the scope of realizing extremely long group delays by taking advantage of singularities.Peer reviewe

Metabolomic landscape of macrophage discloses an anabolic signature of dengue virus infection and antibody-dependent enhancement of viral infection.

Dengue virus (DENV) infection causes dengue fever, the most prevalent arthropod-transmitted viral disease worldwide. Viruses are acellular parasites and obligately rely on host cell machinery for reproduction. Previous studies have indicated metabolomic changes in endothelial cell models and sera of animal models and patients with dengue fever. To probe the immunometabolic mechanism of DENV infection, here, we report the metabolomic landscape of a human macrophage cell model of DENV infection and its antibody-dependent enhancement. DENV infection of THP-1-derived macrophages caused 202 metabolic variants, of which amino acids occupied 23.7%, fatty acids 21.78%, carbohydrates 10.4%, organic acids 13.37%, and carnitines 10.4%. These metabolomic changes indicated an overall anabolic signature, which was characterized by the global exhaustion of amino acids, increases of cellular fatty acids, carbohydrates and pentoses, but decreases of acylcarnitine. Significant activation of metabolic pathways of glycolysis, pentose phosphate, amino acid metabolism, and tricarboxylic acid cycle collectively support the overall anabolism to meet metabolic demands of DENV replication and immune activation by viral infection. Totally 88 of 202 metabolic variants were significantly changed by DENV infection, 36 of which met the statistical standard (P1.5) of differentially expressed metabolites, which were the predominantly decreased variants of acylcarnitine and the increased variants of fatty acids and carbohydrates. Remarkably, 11 differentially expressed metabolites were significantly distinct between DENV only infection and antibody-dependent enhancement of viral infection. Our data suggested that the anabolic activation by DENV infection integrates the viral replication and anti-viral immune activation