Adjustable SQUID-resonator direct coupling in microwave SQUID multiplexer for TES microcalorimeter array

Nakashima, Yoshiki; Hirayama, Fuminori; Kohjiro, Satoshi; Yamamori, Hirotake; Nagasawa, Shuichi; Yamasaki, Noriko Y.; Mitsuda, Kazuhisa

doi:10.1587/elex.14.20170271

Cited by 10 publications

(2 citation statements)

References 14 publications

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“…Our possible setup is composed of two

bold-italicλ / 4

transmission line resonators coupled by a superconducting quantum interference device (SQUID) through the current ( Figure a). This coupling allows us to tune the cavity frequency and the coupling strength between each resonator . Moreover, two transmon qubits are capacitively coupled to the resonator through the voltage at the ends of the transmission line resonator.…”

Section: Implementation In Superconducting Circuitsmentioning

confidence: 99%

Enhanced Quantum Synchronization via Quantum Machine Learning

et al. 2019

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The quantum synchronization between a pair of two‐level systems inside two coupled cavities is studied. By using a digital–analog decomposition of the master equation that rules the system dynamics, it is shown that this approach leads to quantum synchronization between both two‐level systems. Moreover, in this digital–analog block decomposition, the fundamental elements of a quantum machine learning protocol can be identified, in which the agent and the environment (learning units) interact through a mediating system, namely, the register. If the algorithm can be additionally equipped with a classical feedback mechanism, which consists of projective measurements in the register, reinitialization of the register state, and local conditional operations on the agent and environment subspace, a powerful and flexible quantum machine learning protocol emerges. Indeed, numerical simulations show that this protocol enhances the synchronization process, even when every subsystem experiences different loss/decoherence mechanisms, and gives the flexibility to choose the synchronization state. Finally, an implementation is proposed, based on current technologies in superconducting circuits.

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“…Our possible setup is composed of two

bold-italicλ / 4

Section: Implementation In Superconducting Circuitsmentioning

confidence: 99%

Enhanced Quantum Synchronization via Quantum Machine Learning

et al. 2019

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“…While varnish or silver paste are used to mount a chip with low dissipation power such as superconducting sensors and so on [24,25], the use of them resulted in a significant temperature increase in the voltage standard chip due to large dissipation power. Thus, a silicon chip is solderbonded to a copper substrate to achieve good thermal contact between the chip and a cryocooler.…”

Section: Packaging For Cryocoolermentioning

confidence: 99%

Reliable packaging of Josephson voltage standard circuit for cryocooler operation

Yamamori

Maruyama

Amagai

et al. 2019

IEICE Electron. Express

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Reliable and easy fabricated packaging for a Josephson voltage standard circuit was proposed and the thermal stress and temperature distribution in the chip were numerically analyzed. The chip for programmable Josephson voltage standard circuits was bonded with InSn solder to a copper plate to achieve good thermal contact. Although this packaging allowed very good thermal contact, the chip sometimes broke due to thermal stress caused by a difference in the expansion coefficient between silicon and copper. Slits were thus added to the copper plate to reduce the thermal stress. The numerical analysis suggested that the slits reduce the thermal stress in the voltage standard chip, and thus reduce the risk of the chip cracking when it is cooled. The numerical analysis also suggested that the temperature increase in the chip was about 1 mK which caused a negligible reduction in the operating margin of the PJVS operation.

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