Macroscopic Quantum Mechanics The CW-S-T-E Natural Unit System

Recently there has been interest in macroscopic systems which can be described in terms of the quantum dynamics of the same collective variables which describe their classical behavior. In particular, there has been considerable interest in the following questions: (1) Is it possible to observe unambiguous evidence of the quantum-mechanical nature of a macroscopic collective coordinate? (2) In what way is the quantum mechanics of a macroscopic variable different from that of a microscopic variable or, in other words, what is the effect of dissipation on the dynamics of a quantum-mechanical system? Spectroscopic evidence of the quantization of energy levels can be found by measuring the system's response to an applied ac perturbation, exploiting the quantum-mechanical relation between energy and frequency. The specific system studied is a superconducting quantum interference device (SQUID). It is shown that a time-varying magnetic field through the superconducting loop in a rf SQUID can cause transitions between different fluxoid states. The role of dissipation is discussed in detail, and it is shown that in the case that dissipation is characterized by linear damping in the classical limit, the photon-absorption process depends critically on the ratio of the resistance of the weak link to the fundamental unit of resistance h/ ${e}^{2}$ . .AERecently there has been interest in macroscopic systems which can be described in terms of the quantum dynamics of the same collective variables which describe their classical behavior. In particular, there has been considerable interest in the following questions: (1) Is it possible to observe unambiguous evidence of the quantum-mechanical nature of a macroscopic collective coordinate? (2) In what way is the quantum mechanics of a macroscopic variable different from that of a microscopic variable or, in other words, what is the effect of dissipation on the dynamics of a quantum-mechanical system? Spectroscopic evidence of the quantization of energy levels can be found by measuring the system's response to an applied ac perturbation, exploiting the quantum-mechanical relation between energy and frequency. The specific system studied is a superconducting quantum interference device (SQUID). It is shown that a time-varying magnetic field through the superconducting loop in a rf SQUID can cause transitions between different fluxoid states. The role of dissipation is discussed in detail, and it is shown that in the case that dissipation is characterized by linear damping in the classical limit, the photon-absorption process depends critically on the ratio of the resistance of the weak link to the fundamental unit of resistance h/${e}^{2}$. .AE

Physical review. B, Condensed matterJul 1, 198546 citations

Quantum Mechanics at the Macroscopic Level

A. J. Leggett

Springer series in solid-state sciencesJan 1, 198730 citations

Why Disconnected Steps for Electrons Become Smooth Processes for Galaxies

James E Beecham

Quantum mechanics reveals that nature operates through discrete units of actioncharacterized by Planck's constant, (h). Individual electrons exchange energy in quantizedsteps, possess de Broglie wavelengths, obey Schrödinger evolution, and are subject toHeisenberg uncertainty. Yet galaxies, stars, planets, and fluids exhibit smooth, continuousbehavior seemingly disconnected from these microscopic rules. This apparent divide hastraditionally been interpreted as evidence that quantum mechanics governs only themicroscopic world while classical mechanics governs the macroscopic world.This paper proposes an alternative interpretation within the Space-Phase (SP3) framework.It argues that both quantum and classical behavior arise from the same underlyingconditionable medium. Planck's constant is interpreted not primarily as a property ofmatter or radiation, but as the minimum quantum of reorganization of that medium.Individual particles negotiate the medium one elementary action step at a time, whereasmacroscopic systems involve astronomically large numbers of simultaneousreorganizations whose collective average appears continuous. In this view, classicalmechanics is not separate from quantum mechanics but represents the statistical limit ofcountless microscopic groove transitions occurring together.The proposed groove model offers a physical interpretation of why discontinuousmicroscopic processes naturally become smooth macroscopic dynamics while preservingthe common role of Planck's constant throughout quantum physics.Quantum mechanics reveals that nature operates through discrete units of actioncharacterized by Planck's constant, (h). Individual electrons exchange energy in quantizedsteps, possess de Broglie wavelengths, obey Schrödinger evolution, and are subject toHeisenberg uncertainty. Yet galaxies, stars, planets, and fluids exhibit smooth, continuousbehavior seemingly disconnected from these microscopic rules. This apparent divide hastraditionally been interpreted as evidence that quantum mechanics governs only themicroscopic world while classical mechanics governs the macroscopic world.This paper proposes an alternative interpretation within the Space-Phase (SP3) framework.It argues that both quantum and classical behavior arise from the same underlyingconditionable medium. Planck's constant is interpreted not primarily as a property ofmatter or radiation, but as the minimum quantum of reorganization of that medium.Individual particles negotiate the medium one elementary action step at a time, whereasmacroscopic systems involve astronomically large numbers of simultaneousreorganizations whose collective average appears continuous. In this view, classicalmechanics is not separate from quantum mechanics but represents the statistical limit ofcountless microscopic groove transitions occurring together.The proposed groove model offers a physical interpretation of why discontinuousmicroscopic processes naturally become smooth macroscopic dynamics while preservingthe common role of Planck's constant throughout quantum physics.

Jul 4, 20260 citations

QUANTUM MECHANICS AT THE MACROSCOPIC LEVEL

Anthony J. Leggett

Series on directions in condensed matter physicsAug 1, 198626 citations

{e}^{2}

. .AE