Universal quantum computing with qubits embedded in trapped-ion qudits

Recent developments in qudit-based quantum computing, in particular with trapped ions, open interesting possibilities for scaling quantum processors without increasing the number of physical information carriers. In this work, we propose a method for compiling quantum circuits in the case, where qubits are embedded into qudits of experimentally relevant dimensionalities, $d=3,\ldots,8$, for the trapped-ion platform. In particular, we demonstrate how single-qubit, two-qubit, and multiqubit gates can be realized using single-qudit operations and the Molmer-Sorensen (MS) gate as a basic two-particle operation. We expect that our findings are directly applicable to trapped-ion-based qudit processors.Comment: 7+2 pages, 4+2 figures, 1 tabl

Realization of quantum algorithms with qudits

The paradigm behind digital quantum computing inherits the idea of using binary information processing. The nature in fact gives much more rich structures of physical objects that can be used for encoding information, which is especially interesting in the quantum mechanical domain. In this Colloquium, we review several ideas indicating how multilevel quantum systems, also known as qudits, can be used for efficient realization of quantum algorithms, which are represented via standard qubit circuits. We focus on techniques of leveraging qudits for simplifying decomposition of multiqubit gates, and for compressing quantum information by encoding multiple qubits in a single qudit. As we discuss, these approaches can be efficiently combined. This allows reducing in the number of entangling (two-body) operations and the number of the used quantum information carriers compared to straightforward qubit realizations. These theoretical schemes can be implemented with quantum computing platforms of various nature, such as trapped ions, neutral atoms, superconducting junctions, and quantum light. We conclude with summarizing a set of open problems, whose resolving is an important further step towards employing universal qudit-based processors for running qubit algorithms.Comment: 24 pages, 19 figure

Thermoelectric prospects of nanomaterials with spin-orbit surface bands

Nanostructured composites and nanowire arrays of traditional thermoelectrics like Bi, Bi(1-x)Sb(x) and Bi(2)Te(3) have metallic Rashba surface spin-orbit bands featuring high mobilities rivaling that of the bulk for which topological insulator behavior has been proposed. Nearly pure surface electronic transport has been observed at low temperatures in Bi nanowires with diameter around the critical diameter, 50 nm, for the semimetal-to semiconductor transition. The surface contributes strongly to the thermopower, actually dominating for temperatures T < 100 K in these nanowires. The surface thermopower was found to be -1 T microvolt/(K^2), a value that is consistent with theory. We show that surface electronic transport together with boundary phonon scattering leads to enhanced thermoelectric performance at low temperatures of Bi nanowire arrays. We compare with bulk n-BiSb alloys, optimized CsBi(4)Te(6) and optimized Bi(2)Te(3). Surface dominated electronic transport can be expected in nanomaterials of the other traditional thermoelectrics.Comment: 18 pages, 3 figure

Determination of generations X, Y, Z user preferences in the Russian mobile application market

In the work, the authors reveal the user preferences of the mobile application market. The study is based on the Strauss–Howe generational theory. The mobile application market appears to be dynamic and fast-growing in an environment of exponential growth in consumer demand and a highly competitive environment. In the article, the authors classify and identify categories and subcategories of mobile applications based on their functional and value purpose. This classification formed the basis for determining the dependence based on the analysis of contingency matrices between the preference of the application for its purpose and the age category of the user, which made it possible to identify the relationship between generations of users and their choice of certain types of applications. The text provides a justification for the choice of certain applications on a daily basis by generations X, Y, Z. The relevance of the study lies in the fact that the authors examine a market, the rapid growth of which is conditioned by the global socio-economic situation. The information obtained during the analysis of user preferences of the Russian mobile application market can be used by specialists in determining the target audience of a digital product and developing marketing strategies

The article presents a clinical case of atopic dermatitis complicated by a secondary infection in an Indonesian boy of 8 years old. A review of literary sources.

The article presents a clinical case of atopic dermatitis complicated by a secondary infection in an Indonesian boy of 8 years old. Areviewofliterarysources