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

arXiv:cond-mat/0101075 · Physical Review A

Evidence for adiabatic magnetization of cold DyN Clusters

Simone Pokrant

Published Oct 12, 2000• 25 citations
arXivHTMLPDF

Abstract

Magnetic properties of ${\mathrm{Dy}}_{N}$ clusters in a molecular beam generated with a liquid-helium--cooled nozzle are investigated by Stern-Gerlach experiments. The cluster magnetizations ${\ensuremath{\mu}}_{z}$ are measured as a function of magnetic field $(B=0--1.6$ T) and cluster size $(17<~N<~55).$ The most important observation is the saturation of the magnetization ${\ensuremath{\mu}}_{z}(B)$ at large field strengths. The magnetization approaches saturation following the power law $|{\ensuremath{\mu}}_{z}\ensuremath{-}{\ensuremath{\mu}}_{0}|\ensuremath{\sim}1/\sqrt{B},$ where ${\ensuremath{\mu}}_{0}$ denotes the magnetic moment. This gives evidence for adiabatic magnetization.

DOI
10.1103/physreva.62.051201

Related papers

Stern-Gerlach Deflection of Metallic-Cluster Beams

Walter D. Knight, R. Monot, Eberhard Dietz +1 more

Supersonic argon beams containing clusters of from 1 to 100 potassium atoms show magnetic deflection patterns with three components: atoms, undeflectable clusters comprising mainly even numbers of atoms, and clusters with odd numbers of atoms. The magnetic moments of the light odd clusters are approximately 1${\mathrm{\ensuremath{\mu}}}_{\mathrm{B}}$.

Physical Review Letters•May 15, 1978•50 citations

Double Stern-Gerlach experiments on Mn@Sn12 : Refocusing of a paramagnetic superatom

Thomas M. Fuchs, Rolf Schäfer

We report magnetic double deflection experiments on cryogenically cooled $\mathrm{Mn}@{\mathrm{Sn}}_{12}$ clusters. Refocusing efficiencies of up to 90% are achieved by keeping the magnetic-flux density virtually constant between the two Stern-Gerlach magnets. The spin dynamics are probed by introducing magnetic-flux density variations along the molecular-beam path. We apply a microscopic model for the interpretation of our results taking the coupling of electronic spin and rotational degrees of freedom into account. The combination of our experimental and theoretical results reveals unexpected insights into the interplay between rotation and spin dynamics of small metal clusters depending on magnetic-field modulations.

Physical Review A•Dec 11, 2018•21 citations

Metastability of Free Cobalt and Iron Clusters: A Possible Precursor to Bulk Ferromagnetism

Xiaoshan Xu, Shuangye Yin, Ramiro Moro +3 more

Homonuclear cobalt and iron clusters ${\mathrm{Co}}_{N}$ and ${\mathrm{Fe}}_{N}$ measured in a cryogenic molecular beam exist in two states with distinct magnetic moments ($\ensuremath{\mu}$), polarizabilities, and ionization potentials, indicating distinct valences. The $\ensuremath{\mu}$ is approximately quantized: ${\ensuremath{\mu}}_{N}\ensuremath{\sim}2N{\ensuremath{\mu}}_{B}$ in the ground states and $\ensuremath{\mu}_{N}{}^{*}\ensuremath{\sim}N{\ensuremath{\mu}}_{B}$ in the excited states for Co; ${\ensuremath{\mu}}_{N}\ensuremath{\sim}3N{\ensuremath{\mu}}_{B}$ and $\ensuremath{\mu}_{N}{}^{*}\ensuremath{\sim}N{\ensuremath{\mu}}_{B}$ for Fe. At a large size, the average $\ensuremath{\mu}$ of the two states converges to the bulk value with diminishing ionization potential differences. The experiments suggest localized ferromagnetism in the two states and that itinerant ferromagnetism emerges from their superposition.

arXiv:1012.4133•Physical Review Letters•Jul 27, 2011•42 citations

Controlling the dimensionality of the Stern-Gerlach effect for neutral atom manipulation

Kevin Melin

The Stern-Gerlach experiment performed in 1922 is a seminal work of modern physics. It was the experiment that first showed the quantized nature of the spin of an atom. This dissertation returns to this early experiment and describes the design, construction, and characterization of a variation that produces a one-dimensional Stern-Gerlach effect, or 1D kick, on a beam of neutral lithium atoms. Our technique relies on the combination of a magnetic field gradient and a strong bias field to generate a one-dimensional force on lithium entrained in a supersonic helium beam. By adjusting the bias field via variable, pulsed currents, we demonstrate the transition from a purely dispersive kick to a one-dimensional kick where off-axis heating of the beam has been eliminated. Pure one-dimensional forces enable access to new atomic and molecular cooling methods that can replace or supplement existing techniques to produce larger samples of cold atoms currently limited by evaporative cooling. Simulations suggest that the proposed magneto-optical cooling utilizing one-dimensional kicks will increase the total number of atoms in cold atom traps by orders of magnitude thus opening applications such as high flux atom lasers and more sensitive atom interferometry.

•May 1, 2019•0 citations

Theory of relaxation of magnetic clusters in a Stern-Gerlach setup

Sushanta Dattagupta, S. D. Mahanti

We use a stochastic theory approach to discuss different scenarios such as ``locked moment'' and ``superparamagnetic'' behavior of magnetic clusters seen in Stern-Gerlach (SG) experiments. A dimensionless parameter $\ensuremath{\lambda}{\ensuremath{\tau}}_{E}$ (where \ensuremath{\lambda} is an internal spin relaxation rate and ${\ensuremath{\tau}}_{E}$ is the time spent by the cluster in the field gradient region) and the initial polarization of the cluster moment are shown to determine sensitively the position of the cluster beam on the SG screen.

Physical review. B, Condensed matter•May 1, 1998•1 citation

Assembly and Test of a Helium Cluster Beam Apparatus for Magnetic Field Studies of Atom and Molecule Doped Helium Nanodroplets

Johannes Lanzersdorfer

•Jan 1, 2008•0 citations
Magnetic properties of DyN{\mathrm{Dy}}_{N}DyN​ clusters in a molecular beam generated with a liquid-helium--cooled nozzle are investigated by Stern-Gerlach experiments. The cluster magnetizations \ensuremathμz{\ensuremath{\mu}}_{z}\ensuremathμz​ are measured as a function of magnetic field (B=0−−1.6(B=0--1.6(B=0−−1.6 T) and cluster size (17< N< 55).(17<~N<~55).(17< N< 55). The most important observation is the saturation of the magnetization \ensuremathμz(B){\ensuremath{\mu}}_{z}(B)\ensuremathμz​(B) at large field strengths. The magnetization approaches saturation following the power law ∣\ensuremathμz\ensuremath−\ensuremathμ0∣\ensuremath∼1/B,|{\ensuremath{\mu}}_{z}\ensuremath{-}{\ensuremath{\mu}}_{0}|\ensuremath{\sim}1/\sqrt{B},∣\ensuremathμz​\ensuremath−\ensuremathμ0​∣\ensuremath∼1/B​, where \ensuremathμ0{\ensuremath{\mu}}_{0}\ensuremathμ0​ denotes the magnetic moment. This gives evidence for adiabatic magnetization.
We report magnetic double deflection experiments on cryogenically cooled Mn@Sn12\mathrm{Mn}@{\mathrm{Sn}}_{12}Mn@Sn12​ clusters. Refocusing efficiencies of up to 90% are achieved by keeping the magnetic-flux density virtually constant between the two Stern-Gerlach magnets. The spin dynamics are probed by introducing magnetic-flux density variations along the molecular-beam path. We apply a microscopic model for the interpretation of our results taking the coupling of electronic spin and rotational degrees of freedom into account. The combination of our experimental and theoretical results reveals unexpected insights into the interplay between rotation and spin dynamics of small metal clusters depending on magnetic-field modulations.
Homonuclear cobalt and iron clusters CoN{\mathrm{Co}}_{N}CoN​ and FeN{\mathrm{Fe}}_{N}FeN​ measured in a cryogenic molecular beam exist in two states with distinct magnetic moments ($\ensuremath{\mu}$), polarizabilities, and ionization potentials, indicating distinct valences. The $\ensuremath{\mu}$ is approximately quantized: ${\ensuremath{\mu}}_{N}\ensuremath{\sim}2N{\ensuremath{\mu}}_{B}$ in the ground states and $\ensuremath{\mu}_{N}{}^{*}\ensuremath{\sim}N{\ensuremath{\mu}}_{B}$ in the excited states for Co; ${\ensuremath{\mu}}_{N}\ensuremath{\sim}3N{\ensuremath{\mu}}_{B}$ and $\ensuremath{\mu}_{N}{}^{*}\ensuremath{\sim}N{\ensuremath{\mu}}_{B}$ for Fe. At a large size, the average $\ensuremath{\mu}$ of the two states converges to the bulk value with diminishing ionization potential differences. The experiments suggest localized ferromagnetism in the two states and that itinerant ferromagnetism emerges from their superposition.
The Stern-Gerlach experiment performed in 1922 is a seminal work of modern physics. It was the experiment that first showed the quantized nature of the spin of an atom. This dissertation returns to this early experiment and describes the design, construction, and characterization of a variation that produces a one-dimensional Stern-Gerlach effect, or 1D kick, on a beam of neutral lithium atoms. Our technique relies on the combination of a magnetic field gradient and a strong bias field to generate a one-dimensional force on lithium entrained in a supersonic helium beam. By adjusting the bias field via variable, pulsed currents, we demonstrate the transition from a purely dispersive kick to a one-dimensional kick where off-axis heating of the beam has been eliminated. Pure one-dimensional forces enable access to new atomic and molecular cooling methods that can replace or supplement existing techniques to produce larger samples of cold atoms currently limited by evaporative cooling. Simulations suggest that the proposed magneto-optical cooling utilizing one-dimensional kicks will increase the total number of atoms in cold atom traps by orders of magnitude thus opening applications such as high flux atom lasers and more sensitive atom interferometry.
We use a stochastic theory approach to discuss different scenarios such as ``locked moment'' and ``superparamagnetic'' behavior of magnetic clusters seen in Stern-Gerlach (SG) experiments. A dimensionless parameter $\ensuremath{\lambda}{\ensuremath{\tau}}_{E}$ (where \ensuremath{\lambda} is an internal spin relaxation rate and ${\ensuremath{\tau}}_{E}$ is the time spent by the cluster in the field gradient region) and the initial polarization of the cluster moment are shown to determine sensitively the position of the cluster beam on the SG screen.