Non-perturbative gadget for topological quantum codes

Many-body entangled systems, in particular topologically ordered spin systems proposed as resources for quantum information processing tasks, often involve highly non-local interaction terms. While one may approximate such systems through two-body interactions perturbatively, these approaches have a number of drawbacks in practice. Here, we propose a scheme to simulate many-body spin Hamiltonians with two-body Hamiltonians non-perturbatively. Unlike previous approaches, our Hamiltonians are not only exactly solvable with exact ground state degeneracy, but also support completely localized quasi-particle excitations, which are ideal for quantum information processing tasks. Our construction is limited to simulating the toric code and quantum double models, but generalizations to other non-local spin Hamiltonians may be possible.Comment: 13 pages, 8 figures, PRL Accepte

Polaron cross-overs and d-wave superconductivity in Hubbard-Holstein model

We present a theoretical study of superconductivity of polarons in the Hubbard-Holstein model. A residual kinematic interaction proportional to the square of the polaron hopping energy between polarons and phonons provides a pairing field for the polarons. We find that superconducting instability in the d-wave channel is possible with small transition temperatures which is maximum in the large to small polaron cross-over region. An s-wave instability is found to be not possible when the effective on-site interaction between polarons is repulsive

Quantum codes give counterexamples to the unique pre-image conjecture of the N-representability problem

It is well known that the ground state energy of many-particle Hamiltonians involving only 2-body interactions can be obtained using constrained optimizations over density matrices which arise from reducing an N-particle state. While determining which 2-particle density matrices are "N- representable" is a computationally hard problem, all known extreme N-representable 2-particle reduced density matrices arise from a unique N-particle pre-image, satisfying a conjecture established in 1972. We present explicit counterexamples to this conjecture through giving Hamiltonians with 2-body interactions which have degenerate ground states that cannot be distinguished by any 2-body operator. We relate the existence of such counterexamples to quantum error correction codes and topologically ordered spin systems.Comment: 4 pages, 1 figur

Synthesis of β-triphosphotriester pronucleotides

Dinucleoside phosphorochloridite were synthesized from phosphorus trichloride and three nucleoside analogues, 3-fluoro-2,3-dideoxythymidine (FLT), 2\u27,3\u27-dideoxy-5-fluoro-3\u27- thiacytidine (FTC), and 2\u27,3\u27-dideoxy-3\u27-thiacytidine (3TC), in a multistep synthesis. Polymerbound N-Boc p-acetoxybenzyl 5¢-O-2¢-deoxythymidine was reacted with dinucleoside phosphorochloridite in the presence of 2,6-lutidine, followed by the reaction with dodecyl alcohol and 5-(ethylthio)-1H-tetrazole, oxidation with tert-butyl hydroperoxide, and acidic cleavage, respectively, to afford the b-triphosphotriester derivatives containing three different nucleosides

Framework for classifying logical operators in stabilizer codes

Entanglement, as studied in quantum information science, and non-local quantum correlations, as studied in condensed matter physics, are fundamentally akin to each other. However, their relationship is often hard to quantify due to the lack of a general approach to study both on the same footing. In particular, while entanglement and non-local correlations are properties of states, both arise from symmetries of global operators that commute with the system Hamiltonian. Here, we introduce a framework for completely classifying the local and non-local properties of all such global operators, given the Hamiltonian and a bi-partitioning of the system. This framework is limited to descriptions based on stabilizer quantum codes, but may be generalized. We illustrate the use of this framework to study entanglement and non-local correlations by analyzing global symmetries in topological order, distribution of entanglement and entanglement entropy.Comment: 20 pages, 9 figure

Desain Sistem Pendingin Ruang Muat Kapal Ikan Tradisional Dengan Menggunakan Campuran Es Kering Dan Cold Ice Yang Berbahan Dasar Propylene Glycol

Penanganan ikan hasil perikanan supaya tetap segar biasanya menggunakan es basah, terutama oleh nelayan tradisional. Penggunaan es basah hanya bertahan dalam waktu singkat. Propylene glycol merupakan salah satu bahan yang mampu menjaga kestabilan suhu rendah. Sehingga sangat efektif dan efisien apabila digunakan sebagai bahan pendingin ikan. Selain tidak membutuhkan tempat yang luas dalam penyimpanannya, propylene glycol mampu mempertahankan suhu rendah dalam waktu yang lama, tidak beracun dan mudah didegradasi oleh lingkungan (ramah lingkungan). Penelitian ini dilakukan untuk mengetahui lama waktu yang dicapai alat pendingin dengan penambahan uap es kering dan propylene glycol. Serta mengetahui mutu ikan dengan menggunakan sistem pendingin yang dirancang dengan bahan dasar propylene glycol. Sistem pendingin ini dirancang dengan menggunakan cool box yang terdiri dari dua box yang terpisah. Coolbox yang pertama sebagai tempat ikan dengan es basah. Coolbox yang ke dua (yang lebih kecil) sebagai tempat es kering dan propylene glycol. Uap dingin dari es kering dan propylene glycol dialirkan ke kotak yang pertama dengan menggunakan blower. Sistem pendingin yang dirancang ini akan mampu mempertahankan suhu rendah dan menjaga kualitas ikan hasil tangkapan tetap segar. Sehingga sistem pendingin yang berbahan dasar propylene glycol akan lebih efektif, efisien dan ramah lingkungan

Chaos in quantum channels

We study chaos and scrambling in unitary channels by considering their entanglement properties as states. Using out-of-time-order correlation functions to diagnose chaos, we characterize the ability of a channel to process quantum information. We show that the generic decay of such correlators implies that any input subsystem must have near vanishing mutual information with almost all partitions of the output. Additionally, we propose the negativity of the tripartite information of the channel as a general diagnostic of scrambling. This measures the delocalization of information and is closely related to the decay of out-of-time-order correlators. We back up our results with numerics in two non-integrable models and analytic results in a perfect tensor network model of chaotic time evolution. These results show that the butterfly effect in quantum systems implies the information-theoretic definition of scrambling

Analisis Kompetensi Guru Sebagai Bagian Dari Pedagogical Content Knowledge Guru Dalam Menerapkan Pendekatan Saintifik Dalam Program Plpg

The purpose of this research is to analyze the competence of teachers as part of the teachers\u27 pedagogical content knowledge in applying scientific approach in Mathematics PLPG (in-service teacher education and professional training) program rayon 138 Yogyakarta, Indonesia, in 2014. The research method used is descriptive with quantitative approach. The subjects of the study consisted of 23 mathematics teachers including mathematics teachers of junior high school, high school and vocational school from Kebumen, Purworejo, and Magelang. Data was collected by filling in a questionnaire at the beginning and end of the training, observing microteaching activities, and documenting the learning material arranged by PLPG participants. Based on the analysis, it can be concluded that PLPG especially PLPG rayon 138 Yogyakarta, Indonesia, in 2014 gives benefits for the development of teachers\u27 PCK, especially in terms of teachers\u27 competence in applying scientific approach. Based on the analysis of learning materials arranged by the teachers and analysis of learning videos, it is known that the majority of the teachers have been able to construct a learning material using scientific approach and implement it properly