Limits, applicability and generalizations of the Landauer's erasure principle

Almost sixty years since Landauer linked the erasure of information with an increase of entropy, his famous erasure principle and byproducts like reversible computing are still subjected to debates in the scientific community. In this work we use the Liouville theorem to establish three different types of the relation between manipulation of information by a logical gate and the change of its physical entropy, corresponding to three types of the final state of environment. A time-reversible relation can be established when the final states of environment corresponding to different logical inputs are macroscopically distinguishable, showing a path to reversible computation and erasure of data with no entropy cost. A weak relation, giving the entropy change of $k \ln 2$ for an erasure gate, can be deduced without any thermodynamical argument, only requiring the final states of environment to be macroscopically indistinguishable. The common strong relation that links entropy cost to heat requires the final states of environment to be in a thermal equilibrium. We argue in this work that much of the misunderstanding around the Landauer's erasure principle stems from not properly distinguishing the limits and applicability of these three different relations. Due to new technological advances, we emphasize the importance of taking into account the time-reversible and weak types of relation to link the information manipulation and entropy cost in erasure gates beyond the considerations of environments in thermodynamic equilibrium.Comment: 26 pages, 3 figure

A general-covariant concept of particles in curved background

A local current of particle density for scalar fields in curved background is constructed. The current depends on the choice of a two-point function. There is a choice that leads to local non-conservation of the current in a time-dependent gravitational background, which describes local particle production consistent with the usual global description based on the Bogoliubov transformation. Another choice, which might be the most natural one, leads to the local conservation of the current.Comment: 9 pages, the paper is modified such that it includes the corrections that will be published in the erratu

Obnavljanje kiralne simetrije u linearnom sigma modelu

We study the chiral phase transition in the linear sigma model at nonzero temperature and baryon density with Nf ≥ 3 quark flavours and Nc colours. One-loop calculations for Nf = 3 predict a first-order phase transition at both µ = 0 and µ/=0. We also compare the results with the already existing results for Nf = 2.Proučava se kiralni fazni prijelaz u linearnom sigma modelu pri konačnoj temperaturi i barionskoj gustoći sa Nf ≥ 3 kvarkovska okusa i Nc boja. Računi s jednom petljom za Nf = 3 predviđaju prijelaz prve vrste za µ = 0 i µ /=0. Svoje rezultate uspoređujemo s objavljenim rezultatima za Nf = 2

Obnavljanje kiralne simetrije u linearnom sigma modelu

We study the chiral phase transition in the linear sigma model at nonzero temperature and baryon density with Nf ≥ 3 quark flavours and Nc colours. One-loop calculations for Nf = 3 predict a first-order phase transition at both µ = 0 and µ/=0. We also compare the results with the already existing results for Nf = 2.Proučava se kiralni fazni prijelaz u linearnom sigma modelu pri konačnoj temperaturi i barionskoj gustoći sa Nf ≥ 3 kvarkovska okusa i Nc boja. Računi s jednom petljom za Nf = 3 predviđaju prijelaz prve vrste za µ = 0 i µ /=0. Svoje rezultate uspoređujemo s objavljenim rezultatima za Nf = 2

Would Bohr be born if Bohm were born before Born?

I discuss a hypothetical historical context in which a Bohm-like deterministic interpretation of the Schrodinger equation could have been proposed before the Born probabilistic interpretation and argue that in such a context the Copenhagen (Bohr) interpretation would probably have never achieved great popularity among physicists.Comment: 5 pages, revised, accepted for publication in Am. J. Phy

Comment on "Critical assessment of the Schrodinger picture of quantum mechanics"

Recently, Faria et al [Phys. Lett. A 305 (2002) 322] discussed an example in which the Heisenberg and the Schrodinger pictures of quantum mechanics gave different results. We identify the mistake in their reasoning and conclude that the example they discussed does not support the inequivalence of these two pictures.Comment: 4 pages, revised, to appear in Phys. Lett.

Bohmian mechanics in relativistic quantum mechanics, quantum field theory and string theory

I present a short overview of my recent achievements on the Bohmian interpretation of relativistic quantum mechanics, quantum field theory and string theory. This includes the relativistic-covariant Bohmian equations for particle trajectories, the problem of particle creation and destruction, the Bohmian interpretation of fermionic fields and the intrinsically Bohmian quantization of fields and strings based on the De Donder-Weyl covariant canonical formalism.Comment: 6 pages, talk given at Third International Workshop DICE2006, Piombino, Italy, September 11-15, 200

Arrival time from the general theory of quantum time distributions

We further develop the general theory of quantum time distributions introduced in arXiv:2010.07575 and apply it to find the distribution of arrival times at the detector. Even though the Hamiltonian in the absence of detector is hermitian, the time evolution of the system before detection involves dealing with a non-hermitian operator obtained from the projection of the hermitian Hamiltonian onto the region in front of the detector. Such a formalism eventually gives rise to a simple and physically sensible analytical expression for the arrival time distribution, for arbitrary wave packet moving in one spatial dimension with negligible distortion.Comment: 10 pages, improved version accepted for publication in Eur. Phys. J. Plu

Passive quantum measurement: Arrival time, quantum Zeno effect and gambler's fallacy

Classical measurements are passive, in the sense that they do not affect the physical properties of the measured system. Normally, quantum measurements are not passive in that sense. In the infinite dimensional Hilbert space, however, we find that quantum projective measurement can be passive in a way which is impossible in finite dimensional Hilbert spaces. Specifically, we find that expectation value of a hermitian Hamiltonian can have an imaginary part in the infinite dimensional Hilbert space and that such an imaginary part implies a possibility to avoid quantum Zeno effect, which can physically be realized in quantum arrival experiments. The avoidance of quantum Zeno effect can also be understood as avoidance of a quantum version of gambler's fallacy, leading to the notion of passive quantum measurement that updates information about the physical system without affecting its physical properties. The arrival time probability distribution of a particle is found to be given by the flux of the probability current. Possible negative fluxes correspond to regimes at which there is no arrival at all, physically understood as regimes at which the particle departs rather than arrives.Comment: 15 pages, 1 figure, version accepted for publication in Fortschr. Phy