Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Prototype model for nuclear spin conversion in molecules: The case of "hydrogen"

Il'ichov, L.V.

Published Jan 1, 1999• 3 citations
OpenAlex

Abstract

Using the concept of the so-called quantum relaxation, we build a semiphenomenological model for ortho-para conversion of nuclear spin isomers of hydrogen-type molecules.

Related papers

Spin Isomers of Hydrogen Molecules as a Potential Two-Level System for Encoding Quantum Information

Vyacheslav Voloshyn, Oleg Klenin

Introduction. In modern information theory, the idea of a fundamental connection between information, quantum mechanics and thermodynamics is becoming increasingly important. After the works of R. Landauer, the principle was formulated, which became the basis of a new field — information thermodynamics. On the other hand, the search for new ways of physical realization of qubits remains an urgent scientific problem. One of the potential quantum systems that has a natural two-state structure is the ortho- and para-states of the hydrogen molecule. The purpose. Hypothetical identification of the physical essence of the quantum-mechanical nature of information in the ortho/pair conversion of a hydrogen molecule, from the point of view of statistical mechanics and Landauer's thermodynamic principle as a fundamental energy limit for the legalization of information qubits. Results. From the point of view of quantum informatics, ortho/pair hydrogen molecules as quantum spin isomers can behave as different quantum components, because they have different statistical entropy. Therefore, they can be interpreted as two information configurations of one quantum system. Such a system is informationally and thermodynamically ordered in accordance with the Landauer principle and mathematically corresponding to the structure of a qubit or a logical two-level subsystem, isolated from the full four-dimensional Hilbert space of the two spins. The mathematical structure of this system corresponds to a two-level information space, which allows it to be interpreted as a potential model of an elementary quantum information carrier. Due to its antisymmetric structure, it shows increased adaptation in accordance with certain types of magnetic fluctuations, ions, chemical interactions and collective perturbations. The effective use of spin isomers as information carriers requires controlled quantum media, the creation of cryogenic and magnetic influences or isolated systems, and the synchronization of information operations with characteristic coherence times. Conclusions. The proposed conceptual and quantum-information analysis allows us to formulate a consistently consistent system of assumptions regarding a possible hypothesis about the interpretation of spin isomers of hydrogen as potential natural carriers of artificial quantum information. The practical implementation of this concept on the example of hydrogen requires further theoretical and experimental research aimed at studying the mechanisms of coordinated coherence, control of ortho/para-conversion and the possibilities of controlling the spin states of molecular systems. Keywords: quantum information, hydrogen isomer, qubit, entropy, spin conversion, ortho/pair transitions, quantum computer, Landauer's principle.

Cybernetics and Computer Technologies•Sep 29, 2026•0 citations

Quantum Mechanical Model of the Hydrogen Atom

Andrés Felipe Ortiz, Snehanshu Saha

•Jan 1, 2011•0 citations

Theoretical model for enrichment of CH3F nuclear-spin isomers by resonant microwave radiation

O. I. Permyakova, Ernest ILISCA, P. L. Chapovsky

A theoretical model of coherent control of nuclear-spin isomers by microwave radiation has been developed. The model accounts the M degeneracy of molecular states and molecular center-of-mass motion. The model has been applied to the ${}^{13}{\mathrm{CH}}_{3}\mathrm{F}$ molecules. Microwave radiation excites the para state $(J=11,$ $K=1)$ which is mixed by the nuclear-spin-spin interaction with the ortho state (9,3). Dependences of the isomer enrichment and conversion rates on the radiation frequency have been calculated. Both spectra consist of two resonances situated at the centers of nuclear-spin-allowed and -forbidden transitions of the molecule. Larger enrichment, up to 7%, can be produced by strong radiation resonant to the forbidden transition. The spin conversion rate can be increased by two orders of magnitude at this resonance.

arXiv:physics/0208099•Physical Review A•Mar 24, 2003•3 citations

ChemInform Abstract: What Quantum Mechanics for Nuclear Magnetic Resonance?

R. Lenk

ChemInform•May 13, 1986•0 citations

On Deriving Relaxation Equations for Nuclear Spins

W. Apel, Yu. A. Bychkov

Springer eBooks•Jan 1, 2003•0 citations

Quantum Zeno Effect Induced by Collisions

B. Nagels, L.J.F. Hermans, P. L. Chapovsky

It is proven experimentally that the ortho-para conversion of the nuclear spin isomers of ${}^{13}{\mathrm{CH}}_{3}\mathrm{F}$ molecules can be slowed down by increasing the gas pressure. The observed ``freezing'' of the molecular quantum states can be considered as an example of the quantum Zeno effect induced by collisions.

Physical Review Letters•Oct 27, 1997•79 citations
Introduction. In modern information theory, the idea of a fundamental connection between information, quantum mechanics and thermodynamics is becoming increasingly important. After the works of R. Landauer, the principle was formulated, which became the basis of a new field — information thermodynamics. On the other hand, the search for new ways of physical realization of qubits remains an urgent scientific problem. One of the potential quantum systems that has a natural two-state structure is the ortho- and para-states of the hydrogen molecule. The purpose. Hypothetical identification of the physical essence of the quantum-mechanical nature of information in the ortho/pair conversion of a hydrogen molecule, from the point of view of statistical mechanics and Landauer's thermodynamic principle as a fundamental energy limit for the legalization of information qubits. Results. From the point of view of quantum informatics, ortho/pair hydrogen molecules as quantum spin isomers can behave as different quantum components, because they have different statistical entropy. Therefore, they can be interpreted as two information configurations of one quantum system. Such a system is informationally and thermodynamically ordered in accordance with the Landauer principle and mathematically corresponding to the structure of a qubit or a logical two-level subsystem, isolated from the full four-dimensional Hilbert space of the two spins. The mathematical structure of this system corresponds to a two-level information space, which allows it to be interpreted as a potential model of an elementary quantum information carrier. Due to its antisymmetric structure, it shows increased adaptation in accordance with certain types of magnetic fluctuations, ions, chemical interactions and collective perturbations. The effective use of spin isomers as information carriers requires controlled quantum media, the creation of cryogenic and magnetic influences or isolated systems, and the synchronization of information operations with characteristic coherence times. Conclusions. The proposed conceptual and quantum-information analysis allows us to formulate a consistently consistent system of assumptions regarding a possible hypothesis about the interpretation of spin isomers of hydrogen as potential natural carriers of artificial quantum information. The practical implementation of this concept on the example of hydrogen requires further theoretical and experimental research aimed at studying the mechanisms of coordinated coherence, control of ortho/para-conversion and the possibilities of controlling the spin states of molecular systems. Keywords: quantum information, hydrogen isomer, qubit, entropy, spin conversion, ortho/pair transitions, quantum computer, Landauer's principle.
A theoretical model of coherent control of nuclear-spin isomers by microwave radiation has been developed. The model accounts the M degeneracy of molecular states and molecular center-of-mass motion. The model has been applied to the 13CH3F{}^{13}{\mathrm{CH}}_{3}\mathrm{F}13CH3​F molecules. Microwave radiation excites the para state (J=11,(J=11,(J=11, K=1)K=1)K=1) which is mixed by the nuclear-spin-spin interaction with the ortho state (9,3). Dependences of the isomer enrichment and conversion rates on the radiation frequency have been calculated. Both spectra consist of two resonances situated at the centers of nuclear-spin-allowed and -forbidden transitions of the molecule. Larger enrichment, up to 7%, can be produced by strong radiation resonant to the forbidden transition. The spin conversion rate can be increased by two orders of magnitude at this resonance.
It is proven experimentally that the ortho-para conversion of the nuclear spin isomers of 13CH3F{}^{13}{\mathrm{CH}}_{3}\mathrm{F}13CH3​F molecules can be slowed down by increasing the gas pressure. The observed ``freezing'' of the molecular quantum states can be considered as an example of the quantum Zeno effect induced by collisions.