REVIEW
Quantum information entropies of the eigenstates of the Morse potential
Quantum Physics · Submitted 24 Feb 2006 · 18 references
Pith's verdict: A small, honest numerical check of the BBM bound for Morse eigenstates, but the missing numerics methodology and an internal spectrum error keep it below the bar for peer review.
T0 · AI review
Why Pith says this
Highlight any text to comment on it.
Referee report
The paper
The paper claims
Numerical entropies of Morse-potential eigenstates satisfy the Beckner–Bialynicki-Birula–Mycielski bound.
The reading
What carries the argument
The working objects are the exact Morse eigenfunctions $\Psi_n^\lambda(\xi)=N e^{-\xi/2}\xi^{s/2}L_n^s(\xi)$, with $\xi=2\lambda e^{-\alpha x}$, together with the Shannon entropies $S_x=-\int |\psi(x)|^2\ln|\psi(x)|^2\,dx$ and $S_p=-\int |\phi(p)|^2\ln|\phi(p)|^2\,dp$, where $\phi(p)$ is the Fourier transform of $\psi(x)$. The test is the one-dimensional BBM inequality $S_x+S_p\ge1+\ln\pi$. The numerical evaluation of these two integrals, whose integrands are plotted as entropy densities, is the part of the argument that carries the claim.
Extended reading notes
Core claim
The central claim is that for the Morse potential $V(x)=D e^{-\alpha x}(e^{-\alpha x}-2)$, the eigenstates have position and momentum information entropies satisfying $S_x+S_p\ge 1+\ln\pi$. The paper reports numerical values in its table for $n=0,1,2,3$ and several $\lambda$; the smallest listed sum is about $2.167$ for $n=0,\lambda=4$, still above the bound. The authors present this as evidence that the BBM entropic inequality holds for the Morse potential, and they note that as $\lambda$ increases (deeper well, closer to an oscillator) the entropy sum falls toward the bound.
Load-bearing premise
The claim rests on the numerical quadrature being accurate: the paper gives no grid spacing, integration limits, or convergence checks for the entropy integrals or the Fourier transform that yields $\phi(p)$, so the tabulated sums are taken on faith.
Editorial extensions
If this is right
- Every tabulated eigenstate exhibits $S_x+S_p\ge1+\ln\pi$, so the BBM entropic uncertainty bound is numerically respected for the Morse potential.
- As $\lambda$ grows, the entropy sum approaches the lower bound, consistent with the Morse potential becoming more oscillator-like.
- The position entropy density is asymmetric while the momentum entropy density is symmetric, showing localization features that variance-based uncertainty does not capture.
- The table provides a concrete data set that later analytic or numerical work on Morse entropies can benchmark against.
Reading between the lines
- Inference: because the BBM inequality is an established theorem, the paper's real burden is numerical; an independent implementation with stated tolerances would make the table a stronger benchmark.
- Inference: the same numerical procedure applied to other exactly solvable one-dimensional potentials, such as Pöschl–Teller, would show whether the monotone saturation toward $1+\ln\pi$ is specific to the Morse well or generic.
- Inference: the reported trend suggests a scaling relation for the excess entropy $S_x+S_p-(1+\ln\pi)$ as a function of $\lambda$, which the paper does not extract; fitting high-precision values could reveal whether the approach is algebraic or exponential.
Original abstract
The position and momentum space information entropies for the Morse potential are numerically obtained for different strengths of the potential. It is found to satisfy the bound obtained by Beckner, Bialynicki-Birula, and Mycielski. Interesting features of the entropy densities are graphically demonstrated.
The compiled record
The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.
The abstract, sentence by sentence
The position and momentum space information entropies for the Morse potential are numerically obtained for different strengths of the potential. It is found to satisfy the bound obtained by Beckner, Bialynicki-Birula, and Mycielski. Interesting features of the entropy densities are graphically demonstrated.
background contribution method result interpretation main claim
| # | sentence | role | the authors' own work | states the main conclusion | strength |
|---|---|---|---|---|---|
| s0 | The position and momentum space information entropies for the Morse potential are numerically obtained for different strengths of the potential. | contribution 0.58 | 0.93 | 0.11 | asserted 1.00 |
| s1 | It is found to satisfy the bound obtained by Beckner, Bialynicki-Birula, and Mycielski. | result 0.99 | 0.85 | 0.48 | asserted 1.00 |
| s2 | Interesting features of the entropy densities are graphically demonstrated. | result 0.60 | 0.88 | 0.08 | asserted 1.00 |
What was examined, and what was not
- arXiv listing abstract v2
- full text
- figures and tables
- references and citing sentences
- relations to other papers
- P abstract
- S sections
- T body sentences
- C citations
- R cross-paper relations
Figures
Figures reproduced from arXiv:quant-ph/0602203 by the authors.
References
How the literature uses it
2 arXiv papers cite this in 3 sentences
Papers citing it · 1 sentence without a confident label
Uses its method or tool 1 paper
-
Using the definition for the Shannon information entropies in position and momentum basis [ref] [ref] [ref] : [equation] [equation] these satisfy the inequality: [equation] In table 3 we calculate then quantities for the six potentials.
Riemann Hypothesis, Modified Morse Potential and Supersymmetric Quantum Mechanics · Shannon information inequality · 0.84
Cites it as background 1 paper
-
The Laguerre polynomials are known to play a crucial role not only in applied and computational mathematics [ref] , mathematical physics [ref] , combinatorics [ref] , information theory [ref] , quantum algebras [ref] , asymptotics [ref] and theory of special functions [ref] , but also in non-relativisitic, relativistic and supersymmetric quantum mechanics [ref] , atomic and molecular physics [ref] and D-dimensional physics [ref] .
Direct spreading measures of Laguerre polynomials · Introduction · 0.87
Discussion
Disagree with the review, or know something it missed? Leave a comment, highlight any passage above to comment on it, or challenge this review formally.