Using machine learning to improve multi-qubit state discrimination of trapped ions from uncertain EMCCD measurements.

This paper proposes a residual network (ResNet)-based convolutional neural network (CNN) model to improve multi-qubit state measurements using an electron-multiplying charge-coupled device (EMCCD). The CNN model is developed to simultaneously use the intensity of pixel values and the shape of ion images in determining the quantum states of ions. In contrast, conventional methods use only the intensity values.

Micromotion compensation of trapped ions by qubit transition and direct scanning of dc voltages.

Excess micromotion is detrimental to accurate qubit control of trapped ions, thus measuring and minimizing it is crucial. In this paper, we present a simple approach for measuring and suppressing excess micromotion of trapped ions by leveraging the existing laser-driven qubit transition scheme combined with direct scanning of dc voltages. The compensation voltage is deduced by analyzing the Bessel expansion of a scanned qubit transition rate.

A New Measurement Method for High Voltages Applied to an Ion Trap Generated by an RF Resonator.

A new method is proposed to measure unknown amplitudes of radio frequency (RF) voltages applied to ion traps, using a pre-calibrated voltage divider with RF shielding. In contrast to previous approaches that estimate the applied voltage by comparing the measured secular frequencies with a numerical simulation, we propose using a pre-calibrated voltage divider to determine the absolute amplitude of large RF voltages amplified by a helical resonator. The proposed method does not require measurement of secular frequencies and completely removes uncertainty caused by limitations of numerical simulations.

Observation of Hong-Ou-Mandel interference with scalable Yb-photon interfaces.

We present a compact optical design for a scalable trapped ion quantum processor employing a single high numerical aperture lens for the excitation of ions and collection of photons, both of which are essential for remote entanglement generation. We verified the design by performing a quantum interference experiment between two photons generated by two sets of the proposed design and observed a 82(3) % suppression of coincidence within 8.13 ns time window when the two photons became indistinguishable.

Ultralow bending loss fibers with higher-order mode strippers.

We propose and demonstrate bend-insensitive fibers equipped with higher-order mode strippers. The mode stripper is realized by filling a section of air holes with epoxy to attenuate any higher-order modes that are excited at fiber junctions and are confined by the air holes surrounding the core. We found that the higher-order modes are well suppressed with 5 cm-long epoxy columns.

Antiplatelet and antithrombotic activity of indole-3-carbinol in vitro and in vivo.

Indole-3-carbinol, a natural compound found in cruciferous vegetables, is known to have anticancer activity. In the present study, the antiplatelet and antithrombotic activities of indole-3-carbinol were investigated in vitro and in vivo. Indole-3-carbinol significantly inhibited collagen-induced platelet aggregation in human platelet rich plasma (PRP) in a concentration-dependent manner.