The ontology of Bohmian mechanics includes both the universal wave function (living in 3N-dimensional configuration space) and particles (living in ordinary 3-dimensional physical space). Proposals for understanding the physical significance of the wave function in this theory have included the idea of regarding it as a physicallyreal field in its 3N-dimensional space, as well as the idea of regarding it as a law of nature. Here we introduce and explore a third possibility in which the configuration space wave function is simply eliminated-replaced by a set of single-particle pilotwave fields living in ordinary physical space. Such a re-formulation of the Bohmian pilot-wave theory can exactly reproduce the statistical predictions of ordinary quantum theory. But this comes at the rather high ontological price of introducing an infinite network of interacting potential fields (living in 3-dimensional space) which influence the particles' motion through the pilot-wave fields. We thus introduce an alternative approach which aims at achieving empirical adequacy (like that enjoyed by GRW type theories) with a more modest ontological complexity, and provide some preliminary evidence for optimism regarding the (once popular but prematurely-abandoned) program of trying to replace the (philosophically puzzling) configuration space wave function with a (totally unproblematic) set of fields in ordinary physical space.
In this paper we propose two transistor concepts based on lateral heterostructures of monolayer MoS2, composed of adjacent regions of 1T (metallic) and 2H (semiconducting) phases, inspired by recent research showing the possibility to obtain such heterostructures by electron beam irradiation. The first concept, the lateral heterostructure field-effect transistor, exhibits potential of better performance with respect to the foreseen evolution of CMOS technology, both for high performance and low power applications. Performance potential has been evaluated by means of detailed multi-scale materials and device simulations. The second concept, the planar barristor, also exhibits potential competitive performance with CMOS, and an improvement of orders of magnitude in terms of the main figures of merit with respect to the recently proposed vertical barristor.
Weak values allow the measurement of observables associated with noncommuting operators. Up to now, position-momentum weak values have been mainly developed for (relativistic) photons. In this Letter, a proposal for the measurement of such weak values in typical electronic devices is presented. Inspired by the Ramo-Shockley-Pellegrini theorem that provides a relation between current and electron velocity, it is shown that the displacement current measured in multiterminal configurations can provide either a weak measurement of the momentum or strong measurement of position. This proposal opens new opportunities for fundamental and applied physics with state-ofthe-art electronic technology. As an example, a setup for the measurement of the Bohmian velocity of (nonrelativistic) electrons is presented and tested with numerical experiments.Introduction.-Nowadays, there is a rapidly growing interest in weak measurements and weak values [1-4], both from fundamental and applied points of view. Since weak values (a weak measurement postselected by a strong measurement) provide information on incompatible observables associated with noncommuting operators, relevant topics of quantum mechanics, such as the tunneling times [5], Hardy's paradox [6,7], Leggett-Garg inequalities [8,9], and quantum amplification [10][11][12], are being revisited. Especially attractive is the simultaneous measurement of position and momentum: a set of weak measurements of position postselected by a strong measurement of momentum is proportional to the wave function of the system [13,14], while a weak measurement of momentum postselected by a strong measurement of position gives the local velocity of a quantum particle [15,16].Most experimental techniques for weak values are developed for photons, whose technology is not easily transferable to industry based on electronics. The few proposals dealing with weak measurements in solid-state systems [17-22] use particle current measurement (i.e., electron charge detection). Instead, we propose measuring displacement current (i.e. time dependent variations of the electric field) to get information on the position and momentum of a quantum state. Similar to Landauer's proposal [23] which demonstrates that the measured dc current provides information of the quantum transmission coefficient, here, we show that the weak measurement of the ac current flowing through a (properly prepared multiterminal) electron device provides information on the whole quantum state. This new proposal opens original routes to study, both, fundamental physics and quantum engineering.As an example of the potentialities of our proposal, inspired by the old classical works of Shockley and Ramo [24,25], we discuss the measurement of the local (Bohmian) velocity (i.e. the current density divided by the modulus of the wave function) for an electron. Such velocity is obtained from a weak value constructed from two measurements of the displacement current on two different metallic surfaces belonging to a multiterminal
Without access to the full quantum state, modeling dissipation in an open system requires approximations. The physical soundness of such approximations relies on using realistic microscopic models of dissipation that satisfy completely positive dynamical maps. Here we present an approach based on the use of the Bohmian conditional wave function that, by construction, ensures a completely positive dynamical map for either Markovian or non-Markovian scenarios, while allowing the implementation of realistic dissipation sources. Our approach is applied to compute the current-voltage characteristic of a resonant tunneling device with a parabolic-band structure, including electron-lattice interactions. A stochastic Schrödinger equation is solved for the conditional wave function of each simulated electron. We also extend our approach to (graphene-like) materials with a linear band-structure using Bohmian conditional spinors for a stochastic Dirac equation.
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