Experimental verification of the commutation relation for Pauli spin operators using single-photon quantum interference

We report experimental verification of the commutation relation for Pauli spin operators using quantum interference of the single-photon polarization state. By superposing the quantum operations $\sigma_z \sigma_x$ and $\sigma_x \sigma_z$ on a single-photon polarization state, we have experimentally implemented the commutator, $[\sigma_{z}, \sigma_{x}]$, and the anticommutator, $\{\sigma_{z}, \sigma_{x}\}$, and have demonstrated the relative phase factor of $\pi$ between $\sigma_z \sigma_x$ and $\sigma_x \sigma_z$ operations. The experimental quantum operation corresponding to the commutator, $[\sigma_{z}, \sigma_{x}]=k\sigma_y$, showed process fidelity of 0.94 compared to the ideal $\sigma_y$ operation and $|k|$ is determined to be $2.12\pm0.18$.Comment: 4pages, 3 figure

Realizing Physical Approximation of the Partial Transpose

The partial transpose by which a subsystem's quantum state is solely transposed is of unique importance in quantum information processing from both fundamental and practical point of view. In this work, we present a practical scheme to realize a physical approximation to the partial transpose using local measurements on individual quantum systems and classical communication. We then report its linear optical realization and show that the scheme works with no dependence on local basis of given quantum states. A proof-of-principle demonstration of entanglement detection using the physical approximation of the partial transpose is also reported.Comment: 5 pages with appendix, 3 figure

Experimental Implementation of the Universal Transpose Operation

The universal transpose of quantum states is an anti-unitary transformation that is not allowed in quantum theory. In this work, we investigate approximating the universal transpose of quantum states of two-level systems (qubits) using the method known as the structural physical approximation to positive maps. We also report its experimental implementation in linear optics. The scheme is optimal in that the maximal fidelity is attained and also practical as measurement and preparation of quantum states that are experimentally feasible within current technologies are solely applied.Comment: 4 pages, 4 figure

Stress, Coping Style and Nursing Needs for Hospitalized Pregnant Women due to Preterm Labor

PURPOSE: The purpose of this descriptive study was to assess levels of stress, coping style, and nursing needs for hospitalized pregnant women diagnosed with preterm labor. METHODS: Data were collected from 125 pregnant women aged between 20 and 40 years and diagnosed with preterm labor by OBGY units at 3 hospitals. Data were analyzed by frequency, percentage, t-test, and ANOVA with Scheffe test. RESULTS: The level of stress among women was an average of 2.13 out of 4 points, the level of coping style was an average of 2.66, and nursing needs was an average of 2.83 out of 4 points. The level of stress was significantly different by job, length of hospital stay, type of hospital, and history of admission at obstetric unit. The level of coping style was significantly different by age and monthly income. The level of nursing needs was significantly different by type of hospital. Higher level of stress and coping style were related to higher level of nursing needs. There was no significant correlation between stress and coping style. CONCLUSION: The result showed the importance of nursing intervention dealing with stress, coping style and nursing needs for women with preterm labor. Nurses need to provide nursing interventions to reduce the stress, to strengthen the coping style, and to satisfy the nursing needs for pregnant women hospitalized due to preterm labor

Nondestructive discrimination of Bell states between distant parties

Identifying Bell state without destroying it is frequently dealt with in nowadays quantum technologies such as quantum communication and quantum computing. In practice, quantum entangled states are often distributed among distant parties, and it might be required to determine them separately at each location, without inline communication between parties. We present a scheme for discriminating an arbitrary Bell state distributed to two distant parties without destroying it. The scheme requires two entangled states that are pre-shared between the parties, and we show that without these ancillary resources, the probability of non-destructively discriminating the Bell state is bounded by 1/4, which is the same as random guessing. Furthermore, we demonstrate a proof-of-principle experiment through an IonQ quantum computer that our scheme can surpass classical bounds when applied to practical quantum processor.Comment: 9 pages including Appendix, 7 figures and 2 table

Entangling three identical particles via spatial overlap

Quantum correlations between identical particles are at the heart of quantum technologies. Several studies with two identical particles have shown that the spatial overlap and indistinguishability between the particles are necessary for generating bipartite entanglement. On the other hand, researches on the extension to more than two-particle systems are limited by the practical difficulty to control multiple identical particles in laboratories. In this work, we propose schemes to generate two fundamental classes of genuine tripartite entanglement, i.e., GHZ and W classes, which are experimentally demonstrated with three identical photons. We also show that the tripartite entanglement class decays from the genuine entanglement to the full separability as the particles become more distinguishable from each other. Our results support the prediction that particle indistinguishability is a fundamental element for entangling identical particles.Comment: 12 pages including appendix, 5 figures. Comments are welcom