scholarly journals Microscopic Theory of Energy Dissipation and Decoherence in Solid-State Quantum Devices: Need for Nonlocal Scattering Models

Entropy ◽  
2018 ◽  
Vol 20 (10) ◽  
pp. 726 ◽  
Author(s):  
Rita Iotti ◽  
Fausto Rossi
Keyword(s):  
Relaxation Time ◽  
Energy Dissipation ◽  
State Of The Art ◽  
Microscopic Theory ◽  
Quantum Mechanical ◽  
Pauli Blocking ◽  
Quantum Devices ◽  
Semiconductor Nanostructure ◽  
Carrier Interaction ◽  
Intersubband Relaxation

Energy dissipation and decoherence in state-of-the-art quantum nanomaterials and related nanodevices are routinely described and simulated via local scattering models, namely relaxation-time and Boltzmann-like schemes. The incorporation of such local scattering approaches within the Wigner-function formalism may lead to anomalous results, such as suppression of intersubband relaxation, incorrect thermalization dynamics, and violation of probability-density positivity. The primary goal of this article is to investigate a recently proposed quantum-mechanical (nonlocal) generalization (Phys. Rev. B 2017, 96, 115420) of semiclassical (local) scattering models, extending such treatment to carrier–carrier interaction, and focusing in particular on the nonlocal character of Pauli-blocking contributions. In order to concretely show the intrinsic limitations of local scattering models, a few simulated experiments of energy dissipation and decoherence in a prototypical quantum-well semiconductor nanostructure are also presented.

scholarly journals Quantum-mechanical hydration plays critical role in the stability of firefly oxyluciferin isomers: State-of-the-art calculations of the excited states

2020 ◽  
Vol 153 (20) ◽  
pp. 201103
Author(s):  
Yoshifumi Noguchi ◽  
Miyabi Hiyama ◽  
Motoyuki Shiga ◽  
Hidefumi Akiyama ◽  
Osamu Sugino
Keyword(s):  
Excited States ◽  
State Of The Art ◽  
Critical Role ◽  
Quantum Mechanical ◽  
The Stability

Quantum Algorithms

2021 ◽  
pp. 82-101
Author(s):  
Renata Wong ◽  
Amandeep Singh Bhatia
Keyword(s):  
Quantum Computing ◽  
Fault Tolerance ◽  
Quantum Computation ◽  
Quantum Computer ◽  
Quantum Algorithms ◽  
Computer Hardware ◽  
Quantum Mechanical ◽  
Computational Power ◽  
Quantum Devices ◽  
The Core

In the last two decades, the interest in quantum computation has increased significantly among research communities. Quantum computing is the field that investigates the computational power and other properties of computers on the basis of the underlying quantum-mechanical principles. The main purpose is to find quantum algorithms that are significantly faster than any existing classical algorithms solving the same problem. While the quantum computers currently freely available to wider public count no more than two dozens of qubits, and most recently developed quantum devices offer some 50-60 qubits, quantum computer hardware is expected to grow in terms of qubit counts, fault tolerance, and resistance to decoherence. The main objective of this chapter is to present an introduction to the core quantum computing algorithms developed thus far for the field of cryptography.

scholarly journals Microscopic theory of energy dissipation and decoherence in solid-state systems: A reformulation of the conventional Markov limit

2012 ◽  
Vol 249 (11) ◽  
pp. 2125-2136 ◽  
Author(s):  
Michele Pepe ◽  
David Taj ◽  
Rita Claudia Iotti ◽  
Fausto Rossi
Keyword(s):  
Solid State ◽  
Energy Dissipation ◽  
Microscopic Theory ◽  
Markov Limit

scholarly journals EMPIRICAL CONSTRAINTS ON VACUUM DECAY IN THE STRINGY LANDSCAPE

2007 ◽  
Vol 22 (14n15) ◽  
pp. 2661-2672
Author(s):  
R. PLAGA
Keyword(s):  
State Of The Art ◽  
Landscape Dynamics ◽  
Quantum Mechanical ◽  
Born Rule ◽  
Vacuum Decay ◽  
Gravitational Effects ◽  
Parallel Universes ◽  
Apparent Violation ◽  
Age Of The Universe ◽  
The Universe

It is generally considered as self evident that the lifetime of our vacuum in the landscape of string theory cannot be much shorter than the current age of the universe. Here I show why this lower limit is invalid. A certain type of "parallel universes" is a necessary consequence of the string-landscape dynamics and might well allow us to "survive" vacuum decay. As a consequence our stringy vacuum's lifetime is empirically unconstrained and could be very short. Based on this counterintuitive insight I propose a novel type of laboratory experiment that searches for an apparent violation of the quantum-mechanical Born rule by gravitational effects on vacuum decay. If the lifetime of our vacuum should turn out to be shorter than 6 ×10-13 seconds such an experiment is sufficiently sensitive to determine its value with state-of-the-art equipment.

scholarly journals Experimental Analysis on the Cyclic Response of Beam to Column Joints: State-of-the-Art at Salerno University

2014 ◽  
Vol 8 (1) ◽  
pp. 227-247 ◽  
Author(s):  
M. Latour ◽  
G. Rizzano
Keyword(s):  
Energy Dissipation ◽  
Design Process ◽  
Research Group ◽  
Experimental Analysis ◽  
State Of The Art ◽  
Initial Stiffness ◽  
Design Rules ◽  
Cyclic Behaviour ◽  
Analytical Work ◽  
The University

Aiming to provide a contribution to the codification of design rules for dissipative joints to be applied to MRFs, in last five years, a comprehensive experimental and analytical work dealing with the cyclic behaviour of beam-to-column joints has been developed by the research group of the University of Salerno. In particular, the activity has regarded the study of both classical and innovative typologies characterized by the same initial stiffness and resistance but by different hysteretic behaviours due to the different source of energy dissipation supply imposed in the design process. In this paper, the main results of such a study, performed at the laboratory of materials and structures of the University of Salerno, are reported in order to provide an overview on the main mechanisms involved in the energy dissipation of partial-strength connections. A particular attention is given to the design issues by presenting the procedures aimed at providing to the joints adequate characteristics in terms of stiffness, resistance and ductility supply by hierarchically controlling the behaviour of the single joint components. Furthermore, the results of tested joints (classical and innovative) are compared in terms of hysteretic behaviour and energy dissipation supply in order to point out the advantages of the different connecting systems.

scholarly journals Block ramps for stream power attenuation in gravel-bed streams: a review

2020 ◽  
Author(s):  
Rakesh Kumar Chaudhary ◽  
Nayan Sharma ◽  
Zulfequar Ahmad
Keyword(s):  
Energy Dissipation ◽  
Flow Resistance ◽  
Simple Technique ◽  
State Of The Art ◽  
Flow Characteristics ◽  
Stream Power ◽  
Gravel Bed ◽  
The Past ◽  
Gravel Bed Streams ◽  
Block Ramp

Abstract Application of block ramp technique in steep gradient streams for energy dissipation as well as to maintain river stability finds increasing favor amongst researchers and practitioners in river engineering. This paper dwells on a comprehensive state-of-the-art review of flow resistance, energy dissipation,flow characteristics, stability, and drag force on block ramp by various investigators in the past. The forms and equations for each type are thoroughly discussed with the objective of finding the grey areas and gaps. While, more research is warranted further to improve the equations, essential for design analysis. Block ramps can be a promising simple technique to achieve reasonable attenuation of devastating fluvial forces unleashed in gravel-bed streams during cloud bursts.

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