Kentaro Imafuku

ON THE EPR–CHAMELEON EXPERIMENT

We construct a family of classical deterministic dynamical systems (triples formed by a state space, an initial distribution, a dynamics) parametrized by pairs of vectors (a,b) in the unit circle in ℝ2. The systems describe pairs of particles and the dynamics is strictly local, i.e. the dynamics of particle j=1,2 depends only on one of the two unit vectors, but not the other. To each particle one associates a family of ± 1-valued observables (j = 1,2), also parametrized by vectors a in the unit circle in ℝ2. Moreover we assume that, if observable is measured on particle j=1,2, then the dynamics of this particle will be (chameleon effect). Using these ingredients we prove that the dynamics and the initial distributions of the given systems can be chosen in such a way that, if the observable is measured on particle j=1,2, then the EPR correlations -cos(a1-a2) are reproduced. This theoretical construction is then used to realize the following experiment: a central computer S (source) sends the same signal to two local computers A and B. After receiving the signal A (resp. B), chooses one vector a (resp. b) in the unit circle in ℝ2 and computes the value of the corresponding observable (resp. ). These values are uniquely defined by the deterministic dynamics and the choices are independent of one another. The local computers send back to the central one the results of the evaluation of these ±1-valued functions and the central computer evaluates the empirical correlations according to the usual statistical rules. As a result the EPR correlations are reproduced with very good approximation and the Bell inequality is violated by a classical, macroscopic deterministic system performing purely local choices. The program to run the experiment is available from http://volterra.mat.uniroma2.it

Tunneling time based on the quantum diffusion process approach

Abstract We present a time-dependent description of tunneling phenomena, using Nelsons stochastic approach. It appears to be capable to describe individual experimental runs, and provides a new insight into quantum measurement processes. We propose a new way to evaluate the tunneling time in this approach and give the results of numerical simulations.

Interaction of 3-level atom with radiation

The stochastic limit of quantum theory suggests a new, constructive, approach to nonequilibrium phenomena. We illustrate this approach when considering the interaction of 3-level system with a quantum field in a nonequilibrium state. We describe a class of states of the quantum field for which a stationary state drives the system to an inversely populated state. We find that the quotient of the population of the energy levels in the simplest case is described by the double Einstein formula which involves products of two Einstein emission/absorption factors. Emission and absorption of radiation by 3-level atom in nonequilibrium stationary state is described.

Bifurcation phenomenon in spin relaxation

Spin relaxation in a strong-coupling regime (with respect to the spin system) is investigated in detail based on the spin-boson model in a stochastic limit. We find a bifurcation phenomenon in temperature dependence of relaxation constants, which is never observed in the weak-coupling regime. We also discuss inequalities among the relaxation constants in our model and show the well-known relation 2gamma(T)>or=gamma(L), for example, for a wider parameter region than before.

Flow equation approach to diagonal representation of an unbounded Hamiltonian with complex eigenvalues

Abstract The flow equation approach investigated by Wegner et al. is applied to an unbounded Hamiltonian system with a generalization. We show that a well-known quantized complex energy eigenvalues which is related to decay widths can be given with this approach.

STIMULATED EMISSION WITH NON-EQUILIBRIUM STATE OF RADIATION

The stimulated emission from an atom interacting with radiation in nonequilibrium state is considered. The stochastic limit, applied to the nonrelativistic Hamiltonian describing the interaction, shows that the state of atoms, driven by some non-equilibrium state of the eld approaches a stationary state which can continuously emit photon, unlike the case with an equilibrium state.

Note on the EPR-Chameleon experiment

In the past 20 years quantum probability has challanged the widespread belief that classical macroscopic systems cannot, by local independent choices, produce sequences of data whose correlations violate Bell’s inequality. The possibility of such a violation is not a matter of interpretation, but of fact: “local independent choices” means that two separated and non communicating experimenters make measurements but one does not know what the other measures (or even if the other one measures something); correlations are evaluated by means of standard procedures. The present experiment shows that this is not the case: in no way the EPR correlations and related experiments can be considered as a support of the incompatibility of quantum theory with local realistic theories, in particular relativity.

Tunneling time based on the quantum diffusion process approach in multi-channel and optical potential cases

We analyze the effects of inelastic scattering on the tunneling time theoretically, using generalized Nelson’s quantum mechanics. This generalization enables us to describe quantum system with channel couplings and optical potential in a real time stochastic approach, which seems to give us a new insight into quantum mechanics beyond Copenhagen interpretation