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

Physics and Chemistry of Liquids

Spin states ofpara-water andortho-water molecule in gas and liquid phases

Vadim K Konyukhov

Published Apr 1, 2010• 7 citations
Publisher

Abstract

Spin degrees of freedom of water molecule in gas and liquid state were investigated in order to provide a reasonable answer about the unsolved problem of a long-term behaviour of water spin isomers. The approach used involves an assumption that molecules change their spin state from a pure state to a mixed one when they interact with some sorts of adsorbent surface. Some models and conceptions of the quantum information processing were used.

DOI
10.1080/00319100903456154

Related papers

Spin states of para-water and ortho-water molecule in gas and liquid phases

Vadim K Konyukhov

Spin degrees of freedom of water molecule in gas and liquid state were investigated in order to provide a reasonable answer about the unsolved problem of a long-term behavior of water spin isomers. The approach used involves an assumption that molecules change their spin state from a pure state to a mixed one when they interact with some sorts of adsorbent surface. Some models and conceptions of the quantum information processing were used.

arXiv:0909.4169•Sep 23, 2009•2 citations

Spin state of ortho-parawater molecules in liquid

Vadim K Konyukhov

The state of the nuclear spin moments of two protons in the water molecule is considered when the latter is subjected to surrounding liquid and, for this reason, is an open quantum system. The form of the density operator of the mixed state for spin moments is postulated. Spin degrees of freedom of the molecule appear strongly protected against external influences and are not susceptible to external magnetic fields due to the zero nuclear magnetic moment.

Bulletin of the Lebedev Physics Institute•Apr 1, 2009•2 citations

Mixed state of spin moments of two protons in the water molecule and stability of its spin isomers

Vadim K Konyukhov

It is shown that the para-to-ortho water ratio most abundant in the nature is the water molecule existence form most stable to external influences. The assumptions, which are implicitly adopted when singlet and triplet states of the quantum system of two spin moments are independently considered, are discussed.

Bulletin of the Lebedev Physics Institute•Nov 1, 2010•2 citations

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 theory of molecular orientation

Victor V. Albert, Eric Kubischta, Mikhail Lemeshko +1 more

We formulate a quantum phase space for rotational and nuclear-spin states of rigid molecules. For each nuclear spin isomer, we re-derive the isomer's admissible angular momentum states from molecular geometry and nuclear-spin data, introduce its angular position states using quantization theory, and develop a generalized Fourier transform converting between the two. We classify molecules into three types -- asymmetric, rotationally symmetric, and perrotationally symmetric -- with the last type having no macroscopic analogue due to nuclear-spin statistics constraints. We discuss two general features in perrotationally symmetric state spaces that are Hamiltonian-independent and induced solely by symmetry and spin statistics. First, we quantify when and how an isomer's state space is completely rotation-spin entangled, meaning that it does not admit any separable states. Second, we identify isomers whose position states house an internal pseudo-spin or "fiber" degree of freedom, and the fiber's Berry phase or matrix after adiabatic changes in position yields naturally robust operations, akin to braiding anyonic quasiparticles or realizing fault-tolerant quantum gates. We outline how the fiber can be used as a quantum error-correcting code and discuss scenarios where these features can be experimentally probed

arXiv:2403.04572•Mar 7, 2024•0 citations

Nuclear spin conversion in H2O revisited

P. L. Chapovsky, Alexander A. Mamrashev

Conversion of water nuclear-spin isomers by the quantum relaxation phenomenon is revisited and the high stability of water isomers is predicted. As an example, the isomer lifetime is found equal to 18 hours at room temperature and the water vapor pressure equal to $\ensuremath{\simeq}5$ torr. Our calculations correct the prediction of rather short lifetime of water spin isomers, $\ensuremath{\approx}1$ s, made by Cacciani et al. [Phys. Rev. A 85, 012521 (2012)].

Physical Review A•Nov 29, 2021•2 citations
Spin degrees of freedom of water molecule in gas and liquid state were investigated in order to provide a reasonable answer about the unsolved problem of a long-term behaviour of water spin isomers. The approach used involves an assumption that molecules change their spin state from a pure state to a mixed one when they interact with some sorts of adsorbent surface. Some models and conceptions of the quantum information processing were used.
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.
We formulate a quantum phase space for rotational and nuclear-spin states of rigid molecules. For each nuclear spin isomer, we re-derive the isomer's admissible angular momentum states from molecular geometry and nuclear-spin data, introduce its angular position states using quantization theory, and develop a generalized Fourier transform converting between the two. We classify molecules into three types -- asymmetric, rotationally symmetric, and perrotationally symmetric -- with the last type having no macroscopic analogue due to nuclear-spin statistics constraints. We discuss two general features in perrotationally symmetric state spaces that are Hamiltonian-independent and induced solely by symmetry and spin statistics. First, we quantify when and how an isomer's state space is completely rotation-spin entangled, meaning that it does not admit any separable states. Second, we identify isomers whose position states house an internal pseudo-spin or "fiber" degree of freedom, and the fiber's Berry phase or matrix after adiabatic changes in position yields naturally robust operations, akin to braiding anyonic quasiparticles or realizing fault-tolerant quantum gates. We outline how the fiber can be used as a quantum error-correcting code and discuss scenarios where these features can be experimentally probed