Digital Quantum Reality

In the previous post , we have described a Spin Measurement process, performed with a Stern-Gerlach apparatus, in the framework of our Local-Realist theory of quantum mechanics. Despite not being based on complex-valued spinors and matrix operators, our model is able to retrieve the main QM results. In particular, the probability of distribution of spin (spin "up" or "down") at the exit of a SG apparatus, as a function of the initial preparation and of the direction of the magnetic field. One of the most puzzling aspects of QM spin is that, when multiple SG are linked in sequence, they do not act as simple selectors, i.e., filtering out particles with one of the spin values (i.e., states pre-existing to the measurement) and blocking the others. Give a look to the  Wikipedia article  on that, where three experiments are depicted (reproduced below). The first case discloses a quite unsurprising behavior: since only the z-up beam enters the 2nd SG, we expected to ...

One of the most puzzling properties of quantum spin, the intrinsic angular momentum of a particle, is the fact that, once a spatial orientation of spin is measured, it can take only some discrete values. This is in contrast with classical angular momentum that can have a continuous distribution. People say that spin is quantized . The most common measurement procedure is probably by using a Stern-Gerlach apparatus . This measurement consists in sending a beam of particles through an inhomogeneous magnetic field and observing their deflection. With spin-1/2 particles, the result will be that two beams are formed, with some particles deflecting in one direction of the inhomogeinity axis, the others in the opposite direction. This behavior is described within the formulation standard of quantum mechanics by using matricial spin operators. We have already claimed in a previous post that our local-realistic formulation of QM of spin-1/2 particles contains all the elements to correc...

While in the standard formulation of Quantum Mechanics spin is described by a matricial operator, acting on vector quantities (spinors) that describe spin states, in our quest for a local and realist model we have introduced (in an  earlier post ) spin as a (2S+1)-valued attribute of particles. For S = 1/2, our spin s will take values +1 and -1, according to the value of the particle's intrinsic  source spin s 0 and its spin propensity M, which in turn results from the interaction of the intrinsic spin " polarization " and an external magnetic field. We have also described the Reset of spin quantities that occurs when a particle experiences an external force, notably, a magnetic force. Alone, the rules shown in that post are sufficient to explain typical quantum processes such as quantization of spin, the apparent "collapse" of spin states, and generally spin measurement outcomes. This subject is trated in detail in my  2020 ArXiV paper . Let us con...

In our quest for a local and realistic description of quantum mechanics we have developed a full concrete model incorporating many aspects of quantum behavior (quantization, uncertainty principle, wave-particle duality, Born rule, momentum entanglement, etc.), which we have been presenting in previous posts. However, a further class of genuine quantum processes requires a description of an additional particle property, which is intrinsic  spin . I have recently added spin in my model, as reported in my most recent ArXiv publication . With this post, we are going to discuss how spin can emerge from a more fundamental local-realistic mechanism. In addition to source momentum, particles have an intrinsic property that is a rational number comprised between -1 and +1, which we shall call " source spin " and denote as s 0 . In addition to momentum polarization , they also have another vector quantity, that is, three rational numbers {μ 0d } such that We shall call th...

In a previous post , we have discovered that quantum mechanics can described equivalently to standard approaches, and in particular Bell's inequalities  can be violated in a Bell test with momentum-entangled pairs of particles, despite making use of local realist assumptions. However, it is a fact that Bell's theorem and its descendants are regularly used to dismiss any possibility that a local-realist quantum mechanical model could even exist. John Stewart Bell (1928-1990) How happens that our local-realist model captures BI violations and correctly reproduces QM statistics? How to solve this apparent paradox? Despite its mathematical simplicity, interpretation of Bell's theorem has given rise to a vast literature, in particular concerning its assumptions and the conclusions that can be drawn. The usual assumptions used in deriving Bell inequalities are realism (properties of physical systems are elements of reality, outcomes of tests are determined by some hidde...

Within our search for a local-realist description of quantum mechanics, two recent posts have discussed the local-realist rules of motion for particle pairs that are entangled in momentum and how position probability distributions are built upon. We want now to describe a scenario for which these rules allow to retrieve typical quantum correlations between the two particles, which ultimately lead to violations of Bell's inequalities as predicted for QM by Bell's theorem . The scenario consists of a two-slit interferometer, as depicted in the figure. This setting is equivalent to the double-source preparation discussed in the aforementioned posts. The two 'sources' are equally probable and the phase difference at each station is ε (I) = α, ε (II) = β. The detectors are placed at positions x ±  = ±t/(4D), where δ = 2D is the distance between the two slits, a parameter of the stations. In the case of a single station active, with particles emitted ...