arXiv subjects

Chih-Yao Shih

Publications and source records attributed to Chih-Yao Shih.

4 recordsLinked to original sources

arXiv2026

Control the qubit-qubit coupling with double superconducting resonators

We experimentally studied the switching off processes in the double-resonator coupler superconducting quantum circuit. In both frequency and time-domain, we observed the variation of qubit-qubit effective coupling by tuning the frequency differences between qubits and the double-resonator coupler. According to the measurement results, by just shifting about 50 MHz of qubits' frequencies, we can tune the effective qubit-qubit coupling strength from switching off point to two qubit gate point (effective coupling larger than 5 MHz) in double-resonator superconducting quantum circuit.The double-resonator (coupler) superconducting quantum circuit has the advantage of simple fabrications, introducing less flux noises, reducing occupancy of dilution refrigerator cables,which might supply a promising platform for future large-scale superconducting quantum processors.

quant-ph↗

arXiv2025

On-chip Frequency divider in superconducting quantum circuit

Based on the physical process of two-atom simultaneous excitation by single photon, we proposed a frequency dividing scheme in superconducting quantum circuit. The frequency division for a microwave photon consists of two quantum processes: firstly, two qubits share the energy of single photon in high-frequency resonator through the three-body interaction (two qubits and one photon); secondly, part energies of excited state qubits are transferred to corresponding low frequency resonators through two-body interactions (one qubit and one photon). By changing the parameters of pumping pulses, controllable output pulses can be realized through the superconducting frequency divider. The microwave and pulse signals created by the superconducting frequency divider can be used to pump or readout the superconducting qubits, which can greatly reduce the occupation amount of high-frequency cables in dilution refrigerator during the measurement of large scale superconducting quantum chip.

quant-ph↗

arXiv2024

How soap bubbles change shape while maintaining a fixed volume of air?

We combine experiments and theoretical derivations to study the evolution of a stretched soap bubble and compare it with an open film to highlight the effect of volume conservation. We identify a critical length for both surfaces, beyond which a bottleneck develops in the middle and begins to shrink irreversibly, ultimately pinching off into multiple compartments. Before leaving the equilibrium regime, surface energy minimization governs the shape, which can be addressed theoretically via the variational method. In contrast to open films, soap bubble volume conservation introduces a Lagrange multiplier, analogous to a pressure difference, mediating long-range shape evolution. By examining how boundary constraints influence deformation, we contrast the bubble's convex-to-concave transition with the behavior of soap films under similar conditions. Our analysis of equilibrium and breakup regimes reveals critical differences between bubble and film stability profiles, shedding light on universal behaviors in non-equilibrium fluid mechanics, with implications for biological and material sciences.

physics.flu-dyn↗

arXiv2022

Self-similarity with universal property for soap film and bubble in roll-off stage

All children enjoy blowing soap bubbles that also show up in our bath and when we wash dishes. We analyze the thinning and breaking of soap bubble neck when it is stretched. To contrast with the more widely studied film whose boundaries are open, we concentrate on the bubble with a conserved air volume V. Like film (F), non-equilibrium state can be divided into four regimes for bubble (B): (1) roll-off, (2) cusp approach, (3) pinch-off and (4) breakup. We establish the existence of self-similarity in F-1, B-1 and B-3, and universal property in F-1 and B-1 for the profile of soap membrane. The former means that the profile at successive times can be mapped to a master curve after being rescaled by the countdown time τ. Whiles, the latter further requires this master curve to be identical for different ring sizes R for film and different V and R for bubble while keeping V/R^3 fixed. The exhibition of universal property indicates that the process of memory erasing starts earlier than regime 3. We also found that the minimum radius scales as h_{min}~τ^{1/2}, independent of V and pulling speed. Note that the validity of our discussion is limited by the duration of roll-off regime from 10^{-2}~10^{-3} s.

cond-mat.soft↗