Quantum Information Scrambling in a Superconducting Qutrit Processor

The theory of quantum information provides a common language which links disciplines ranging from cosmology to condensed-matter physics. For example, the delocalization of quantum information in strongly-interacting many-body systems, known as quantum information scrambling, has recently begun to unite our understanding of black hole dynamics, transport in exotic non-Fermi liquids, and many-body analogs of quantum chaos. To date, verified experimental implementations of scrambling have dealt only with systems comprised of two-level qubits. Higher-dimensional quantum systems, however, may exhibit different scrambling modalities and are predicted to saturate conjectured speed limits on the rate of quantum information scrambling. We take the first steps toward accessing such phenomena, by realizing a quantum processor based on superconducting qutrits (three-level quantum systems). We implement two-qutrit scrambling operations and embed them in a five-qutrit teleportation algorithm to directly measure the associated out of-time-ordered correlation functions. Measured teleportation fidelities, Favg = 0.568 +- 0001, confirm the occurrence of scrambling even in the presence of experimental imperfections. Our teleportation algorithm, which connects to recent proposals for studying traversable wormholes in the laboratory, demonstrates how quantum information processing technology based on higher dimensional systems can exploit a larger and more connected state space to achieve the resource efficient encoding of complex quantum circuits

Quantum dynamics of simultaneously measured non-commuting observables.

In quantum mechanics, measurements cause wavefunction collapse that yields precise outcomes, whereas for non-commuting observables such as position and momentum Heisenberg's uncertainty principle limits the intrinsic precision of a state. Although theoretical work has demonstrated that it should be possible to perform simultaneous non-commuting measurements and has revealed the limits on measurement outcomes, only recently has the dynamics of the quantum state been discussed. To realize this unexplored regime, we simultaneously apply two continuous quantum non-demolition probes of non-commuting observables to a superconducting qubit. We implement multiple readout channels by coupling the qubit to multiple modes of a cavity. To control the measurement observables, we implement a 'single quadrature' measurement by driving the qubit and applying cavity sidebands with a relative phase that sets the observable. Here, we use this approach to show that the uncertainty principle governs the dynamics of the wavefunction by enforcing a lower bound on the measurement-induced disturbance. Consequently, as we transition from measuring identical to measuring non-commuting observables, the dynamics make a smooth transition from standard wavefunction collapse to localized persistent diffusion and then to isotropic persistent diffusion. Although the evolution of the state differs markedly from that of a conventional measurement, information about both non-commuting observables is extracted by keeping track of the time ordering of the measurement record, enabling quantum state tomography without alternating measurements. Our work creates novel capabilities for quantum control, including rapid state purification, adaptive measurement, measurement-based state steering and continuous quantum error correction. As physical systems often interact continuously with their environment via non-commuting degrees of freedom, our work offers a way to study how notions of contemporary quantum foundations arise in such settings

Attitude of popular Kannada writers towards maintenance of personal library collections

The paper depicts the trends in maintaining personal library collections of popular Kannada writers. The way they organise and use their library collections, means of preserving the collections and the decisions pertaining to weeding out of obsolete and mutilated books, handing over of library collections to other libraries are discussed. The responses were gathered from the popular Kannada writers in the form of questionnaire. The problems faced by the writers in maintaining the library resources are projected in this survey research

Grey literature collections in the libraries of engineering colleges recognised for research in Karnataka: an analytical study

Paper furnishes the holdings of grey literature in the libraries of the engineering colleges recognized for research by the VTU. The organization of the grey sources and the extent of its use are highlighted based on the responses sought from the working librarians and the users of grey literature. The users constitute the faculty engaged in supervising the doctoral research, and the research scholars who have registered for research work.. The importance of grey literature is established on the extent of demand and access in the higher range. The study also covers the opinions expressed by the faculty and researchers on the cooperation and assistance rendered by the librarians while accessing the grey collections. The training requirement of the librarians has also been projected

Preservation of personal library collections of popular Kannada writers

This article deals with the method followed by the Kannada writers in preserving the personal library collections. The problems faced by the popular writers and measures taken to preserve the personal collections are presented based on the responses offered by the popular Kannada writers who have maintained more than 2000 books in their personal libraries at home. The article furnishes measures adopted by the writers in respect of proper preservation of collections. Also dealt are the aspects pertaining to cooperation of family members in preserving the personal collections of writers and the willingness of writers regarding disposal of personal collections when the writers feel they are aged and unable to attend to the work of proper organisation and preservation of personal library collections. Authors have also suggested the measures to be taken for preservation of collections for use of other scholars and public as well

Important issues in maintaining personal libraries of Kannada writers

The paper deals with the extent of cooperation of family members in maintaining personal library collections of popular Kannada writers in Karnataka state. Also considered issues related to whether the writers are willing to spend money for maintaining and preserving personal libraries. Paper depicts the assistance of professional librarians availed by the Kannada writers for systematic maintenance and preservation of personal library collections

Management of obsolete grey literature in engineering research institutions

This paper depicts the findings of the survey research covering 65 engineering institutions which are recognised as research centres in the state of Karnataka, India. Responses have been sought from research supervisors and research scholars as to the extent of the use of obsolete grey collections. Opinions have also been captured from the chief librarians of the 65 research institutions as regards the ways of managing the obsolete grey literature. The following are the areas covered in the study in respect of obsolete grey resources available in these 65 research libraries. ⢠Demand for GL in engineering sciences and technology ⢠Grey Literature collection in English and Foreign languages ⢠Process of weeding-out of obsolete grey literature ⢠Reasons for weeding out of old GL collections ⢠Extent of the use of old GL collections ⢠Weeding-out vis-à -vis Relegation of obsolete GL collections. The study was undertaken during 2007-2010 with the objective of understanding the pattern of obsolescence and the method followed in the libraries to manage the old GL collections in the engineering research institutions. The findings also project the practical methods followed by various libraries as to the weeding out process. Importance of old collections of GL for research vis-à -vis weeding out process adopted by the libraries have been depicted in the study based on the opinions exposed by 1270 researchers, which account for 84.6 of the total population. The summary or core of findings eventually shows that 66.4 of the research supervisors and research scholars hold the view that old collection of GL is of vital source for their research and has to be retained along with active collection in the libraries

Impact of electronic information sources on the academic users in Mysore: an analytical study

The paper depicts the extent of dependency of users of educational and research institutions of Mysore city on the electronic/digital media. The responses of 1000 users and the critical evaluation of 24 subject experts under Delphi study have been gathered to render valid findings and suggestions. The attempt clearly shows the degree of the use of digital information resources vis-à-vis the conventional print media