Two Fundamental Experimental Tests of Nonclassicality with Qutrits

We report two fundamental experiments on three-level quantum systems (qutrits). The first one tests the simplest task for which quantum mechanics provides an advantage with respect to classical physics. The quantum advantage is certified by the violation of Wright's inequality, the simplest classical inequality violated by quantum mechanics. In the second experiment, we obtain contextual correlations by sequentially measuring pairs of compatible observables on a qutrit, and show the violation of Klyachko et al.'s inequality, the most fundamental noncontextuality inequality violated by qutrits. Our experiment tests exactly Klyachko et al.'s inequality, uses the same measurement procedure for each observable in every context, and shows that the violation does not depend on the order of the measurements.Comment: 4 pages, 2 figure

Addendum to "Experimental demonstration of a quantum protocol for Byzantine agreement and liar detection" arXiv:0710.0290

Gao et al. [Phys. Rev. Lett. 101, 208901 (2008)] have described a possible intercept-resend attack for the quantum protocol for detectable Byzantine agreement in Phys. Rev. Lett. 100, 070504 (2008). Here we describe an extension of the protocol which defeats such attacks.Comment: REVTeX4, 2 page

Factors associated with biomedical waste management practices among healthcare personnel at Mbagathi county hospital, Nairobi Kenya

Medical care is vital for life and health, but the waste generated from medical activities presents a problem to human health. Mbagathi county hospital generate 210-341kg infectious and highly infectious waste per day. Lack of work place guideline in many hospitals in developing countries, the implementation of biomedical waste regulations is still below the recommended threshold. This study determined factors associated with biomedical waste management practices among healthcare personnel in Mbagathi county hospital, in Nairobi Kenya. This descriptive cross sectional study used quantitative technique to gather relevant data. Purposive sampling was used to have 195 healthcare personnel as a study subject. Quantitative data were collected using structured questionnaires and analysed using Statistical Package for Social Scientists version 20. A descriptive analysis was used to summary the data and association between variable were tested using chi-square, multivariate and bivariate statistical test. P-values were considered significant at < 0.05. Among the surveyed healthcare personnel, the mean age (±SD) was 31.9 (7.5) years, (86.2%) had tertiary level education and (48.7%) were nurses. A significant voluminous of waste are generated: (96.9%) sharps, (91.3%) pharmaceutical, (90.3%) pathological, (81%) kitchen, (68.7%) incineration ash while the least produced waste reported (64.6%) radioactive wastes. Significant number of study participants (22.6%) had inadequate knowledge on biomedical waste management, with score of ≤ 50%. The nurses scored significantly more with regards to the knowledge on biomedical waste management compared to other healthcare personnel (P =0.001). 31% of study participant did not know when to seal safety bins. 28.2 %, 3.1% of the study participants disagreed and strongly disagreed respectively on management of the biomedical waste at the facility (P=0.005). Out of 195 of study participants, 6.7% had not agreed on recommended practices related to biomedical waste management at the hospital (P =0.001). Waste generated at various departments are source of infection that healthcare personnel and patient are exposed to and variation of knowledge among healthcare personnel is an indication of inadequacy as far as biomedical waste management is concerned. Periodic sensitization of staff using existing friendly channel to convey messages, environmental and occupation health unit to be incorporated in all curriculum for early exposure so as to address concern arising from biomedical waste management in health facility. Keywords: Biomedical waste management, Knowledge, attitude and practice, County Hospital, Capital City of Kenya

Experimental implementation of a Kochen-Specker set of quantum tests

The conflict between classical and quantum physics can be identified through a series of yes-no tests on quantum systems, without it being necessary that these systems be in special quantum states. Kochen-Specker (KS) sets of yes-no tests have this property and provide a quantum-versus-classical advantage that is free of the initialization problem that affects some quantum computers. Here, we report the first experimental implementation of a complete KS set that consists of 18 yes-no tests on four-dimensional quantum systems and show how to use the KS set to obtain a state-independent quantum advantage. We first demonstrate the unique power of this KS set for solving a task while avoiding the problem of state initialization. Such a demonstration is done by showing that, for 28 different quantum states encoded in the orbital-angular-momentum and polarization degrees of freedom of single photons, the KS set provides an impossible-to-beat solution. In a second experiment, we generate maximally contextual quantum correlations by performing compatible sequential measurements of the polarization and path of single photons. In this case, state independence is demonstrated for 15 different initial states. Maximum contextuality and state independence follow from the fact that the sequences of measurements project any initial quantum state onto one of the KS set's eigenstates. Our results show that KS sets can be used for quantum-information processing and quantum computation and pave the way for future developments.Comment: REVTeX, 15 pages, 4 figure