Macroscopic Many-Qubit Interactions in Superconducting Flux Qubits

Superconducting flux qubits are considered to investigate macroscopic many-qubit interactions. Many-qubit states based on current states can be manipulated through the current-phase relation in each superconducting loop. For flux qubit systems comprised of $N$ qubit loops, a general expression of low energy Hamiltonian is presented in terms of low energy levels of qubits and macroscopic quantum tunnelings between the many-qubit states. Many-qubit interactions classified by {\em Ising type- or tunnel-}exchange interactions can be observable experimentally. Flux qubit systems can provide various artificial-spin systems to study many-body systems that cannot be found naturally.Comment: 5 pages, 1 figur

The Aesthetic Values of Transparency in Modern Fashion - Focused on the Transparency Theory

This study considers not only expressive methods of transparency in modern fashion based on the transparency theory but also analysis of characteristics in the transparency

Macroscopic Greenberger-Horne-Zeilinger and W states in flux qubits

We investigate two types of genuine three-qubit entanglement, known as the Greenberger-Horne-Zeilinger (GHZ) and W states, in a macroscopic quantum system. Superconducting flux qubits are theoretically considered in order to generate such states. A phase coupling is proposed to offer enough strength of interactions between qubits. While an excited state can be the W state, the GHZ state is formed at the ground state of the three flux qubits. The GHZ and W states are shown to be robust against external flux fluctuations for feasible experimental realizations

Sympathetic withdrawal is associated with hypotension after hepatic reperfusion

Objective: Post-reperfusion syndrome (PRS), severe hypotension after graft reperfusion during liver transplantation, is an adverse clinical event associated with poorer patient outcomes. The purpose of this study was to determine whether alterations in autonomic control in liver transplant recipients prior to graft reperfusion are associated with the subsequent development of PRS. Methods: Heart rate variability (HRV), systolic arterial blood pressure (SBP) variability, and baroreflex sensitivity of 218 liver transplant recipients were evaluated using 5 min of ECG and arterial blood pressure signals 10 min before graft reperfusion along with other clinical parameters. Logistic regression analyses were performed to assess predictors of PRS occurrence. Results: Seventy-seven patients (35 %) developed PRS while 141 did not. There were significant differences in SBP (110 ± 16 vs. 119 ± 16 mmHg, P < 0.001) and the ratio of low frequency power to high frequency power (LF/HF) of HRV (1.0 ± 1.4 vs. 2.1 ± 3.7, P = 0.003) between the PRS group and No-PRS group. In multivariate logistic regression analysis, predictors were LF/HF (odds ratio 0.817, P = 0.028) and SBP (odds ratio 0.966, P < 0.001). Interpretation: Low LF/HF and SBP measured before hepatic graft reperfusion were significantly correlated with subsequent PRS occurrence, suggesting that sympathovagal imbalance and depressed SBP may be key factors predisposing to reperfusion-related severe hypotension in liver transplant recipients

A New Framework for Digital Taxation

The international tax regime has wide implications for business, trade, and the international political economy. Under current law, multinational enterprises do not pay their fair share of taxes to market countries where profits are generated because market countries are only allowed to tax companies with a physical presence there. Digital companies, like Google and Amazon, can operate entirely online, thereby avoiding market country taxes. Multinationals can also exploit existing tax rules by shifting their profits to low-tax jurisdictions, thereby avoiding taxes in the residence country where their headquarters are located. Recently, a global tax deal was reached to tackle these issues. Proposed by the OECD/G20 Inclusive Framework and endorsed by nearly 140 countries, this global tax deal sets forth two Pillars that reform the outdated international tax regimes. Pillar One addresses digital taxation while Pillar Two addresses a global minimum tax. However, it is doubtful that the global tax deal will be successfully implemented, especially with respect to Pillar One. As the details of Pillar One have become increasingly complex and degraded by political compromises and carve-outs, it risks being a framework without substance. Also, countries are unlikely to repeal an established tax instrument, Digital Services Taxes (“DSTs”), which is an adamant requirement of the United States in adopting Pillar One. This Article offers the first comprehensive critique of the global tax deal and assesses its prospects and problems. It evaluates the U.S. responses to the proposed global deal and to DSTs. It presents the challenges, such as treaty overrides, that will occur if the United States implements Pillar One by executive agreement so as to bypass the treaty ratification. This Article suggests separating the two Pillars to preserve the global minimum tax. Regarding DSTs, the Article provides several empirical studies that demonstrate the harm retaliatory tariffs cause. Finally, it endorses the U.N. digital taxation proposal and proposes a new Data Excise Tax as a normative alternative

A New Framework for Digital Taxation

The international tax regime has wide implications for business, trade, and the international political economy. Under current law, multinational enterprises do not pay their fair share of taxes to market countries where profits are generated because market countries are only allowed to tax companies with a physical presence there. Digital companies, like Google and Amazon, can operate entirely online, thereby avoiding market country taxes. Multinationals can also exploit existing tax rules by shifting their profits to low-tax jurisdictions, thereby avoiding taxes in the residence country where their headquarters are located. Recently, a global tax deal was reached to tackle these issues. Proposed by the OECD/G20 Inclusive Framework and endorsed by nearly 140 countries, this global tax deal sets forth two Pillars that reform the outdated international tax regimes. Pillar One addresses digital taxation while Pillar Two addresses a global minimum tax. However, it is doubtful that the global tax deal will be successfully implemented, especially with respect to Pillar One. As the details of Pillar One have become increasingly complex and degraded by political compromises and carveouts, it risks being a framework without substance. Also, countries are unlikely to repeal an established tax instrument, Digital Services Taxes (“DSTs”), which is an adamant requirement of the United States in adopting Pillar One. This Article offers the first comprehensive critique of the global tax deal and assesses its prospects and problems. It evaluates the U.S. response to the proposed global deal and to DSTs. It presents the challenges, such as treaty overrides, that will occur if the United States implements Pillar One by executive agreement so as to bypass the treaty ratification. This Article suggests separating the two Pillars to preserve the global minimum tax. Regarding DSTs, the Article provides several empirical studies that demonstrate the harm retaliatory tariffs cause. Finally, it endorses the U.N. digital taxation proposal and proposes a new Data Excise Tax as normative alternatives

Implementation of three-qubit Toffoli gate in a single step

Single-step implementations of multi-qubit gates are generally believed to provide a simpler design, a faster operation, and a lower decoherence. For coupled three qubits interacting with a photon field, a realizable scheme for a single-step Toffoli gate is investigated. We find that the three qubit system can be described by four effective modified Jaynes-Cummings models in the states of two control qubits. Within the rotating wave approximation, the modified Jaynes-Cummings models are shown to be reduced to the conventional Jaynes-Cummings models with renormalized couplings between qubits and photon fields. A single-step Toffoli gate is shown to be realizable with tuning the four characteristic oscillation periods that satisfy a commensurate condition. Possible values of system parameters are estimated for single-step Toffli gate. From numerical calculation, further, our single-step Toffoli gate operation errors are discussed due to imperfections in system parameters, which shows that a Toffoli gate with high fidelity can be obtained by adjusting pairs of the photon-qubit and the qubit-qubit coupling strengthes. In addition, a decoherence effect on the Toffoli gate operation is discussed due to a thermal reservoir.Comment: 8 pages, 4 figures, to appear in PR