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

Photonics Letters of Poland

Magnetic trapping on an atom chip

Dobrosława Bartoszek-Bober, Roman Panaś, Tomasz Kawalec

Published Oct 1, 2013• 1 citation
Publisher

Abstract

The article reviews briefly the rapidly evolving field of so-called atom chips for neutral atoms. Emphasis is placed on magnetic microtraps – on-chip Ioffe-Prichard and dimple trap issue is covered in some detail. The experimental setup for cooling and trapping 87Rb atoms is also presented together with some early results of on-chip magnetic trapping. Full Text: PDF References J. Schmiedmayer, "Guiding and trapping a neutral atom on a wire", Phys. Rev. A 52, R13 (1995). CrossRef M. H. Anderson, J. R. Ensher, M. R. Matthews, C. E. Wieman, and E. A. Cornell, "Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor", Science 269, 198 (1995). CrossRef K. B. Davis, M.-O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn et al., "Bose-Einstein Condensation in a Gas of Sodium Atoms", Phys. Rev. Lett. 75, 3969 (1995). CrossRef J. D. Weinstein, K. G. Libbrecht, "Microscopic magnetic traps for neutral atoms", Phys. Rev. A 52, 4004 (1995). CrossRef D. Müller, D. Z. Anderson, R. J. Grow, P. D. D. Schwindt, and E. A. Cornell, "Guiding Neutral Atoms Around Curves with Lithographically Patterned Current-Carrying Wires", Phys. Rev. Lett. 83, 5194 (1999). CrossRef N. H. Dekker, C. S. Lee, V. Lorent, J. H. Thywissen, S. P. Smith, M. Drndi et al., "Guiding Neutral Atoms on a Chip", Phys. Rev. Lett. 84, 1124 (2000). CrossRef J. Reichel, W. Hänsel, and T. W. Hänsch, "Atomic Micromanipulation with Magnetic Surface Traps", Phys. Rev. Lett. 83, 3398 (1999). CrossRef D. Cassettari, B. Hessmo, R. Folman, T. Maier, and J. Schmiedmayer, "Beam Splitter for Guided Atoms", Phys. Rev. Lett. 85, 5483 (2000). CrossRef M. A. Cirone, A. Negretti, T. Calarco, P. Krüger, J. Schmiedmayer, "A simple quantum gate with atom chips", Eur. Phys. J. D 35, 165 (2005). CrossRef W. Hänsel, P. Hommelhoff, T. W. Hänsch, and J. Reichel, "Bose–Einstein condensation on a microelectronic chip", Nature 413, 498 (2001). CrossRef H. Ott, J. Fortagh, G. Schlotterbeck, A. Grossmann, and C. Zimmermann, "Bose-Einstein Condensation in a Surface Microtrap", Phys. Rev. Lett. 87, 230401 (2001). CrossRef Y. Lin, I. Teper, C. Chin, V. Vuletić, "Impact of the Casimir-Polder Potential and Johnson Noise on Bose-Einstein Condensate Stability Near Surfaces", Phys. Rev. Lett. 92, 050404 (2004). CrossRef E. Salim, J. DeNatale, D. Farkas, K. Hudek, S. McBride, J. Michalchuk et al, "Compact, microchip-based systems for practical applications of ultracold atoms", Quantum Inf. Process. 10, 975 (2011). CrossRef S. Groth, Development, "Fabrication and Characterisation of Atom Chips", doctoral dissertation. (2006). R. Folman, P. Krüger, J. Schmiedmayer, J. Denschlag, C. Henkel, "Microscopic atom optics: From wires to an atom chip", Adv. At. Mol. Opt. Phys. 48, 263 (2002). CrossRef A. Arnold, Preparation and Manipulation of an 87Rb Bose-Einstein Condensate (University of Sussex 1999), PhD thesis. D. M. Farkas, K. M. Hudek, E. A. Salim, S. R. Segal, M. B. Squires, and D. Z. Anderson, "A compact, transportable, microchip-based system for high repetition rate production of Bose–Einstein condensates ", Appl. Phys. Lett. 96, 093102 (2010). CrossRef K. Dieckmann, R. J. C. Spreeuw, M. Weidemüller, and J. T. M. Walraven, "Two-dimensional magneto-optical trap as a source of slow atoms", Phys. Rev. A 58, 3891 (1998). CrossRef W. Petrich, M. H. Anderson, J. R. Ensher, and E. A. Cornell, "Behavior of atoms in a compressed magneto-optical trap", J. Opt. Soc. Am. B, 11, 1332 (1994). CrossRef

DOI
10.4302/plp.2013.3.10

Related papers

Permanent magnet atom chips for BEC and microtrap arrays

S. Whitlock, R. Gerritsma, T. Fernholz +1 more

An atom chip is designed to manipulate magnetically trapped ultracold atoms and Bose-Einstein condensates (BECs) near a surface using micro fabricated patterns of current-carrying wires or permanent magnetic materials. We report on experiments using our permanent magnet atom chip.

Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)•Jun 1, 2007•0 citations

Bose-Einstein condensates on a magnetic film atom chip

S. Whitlock

Atom chips are devices used to magnetically trap and manipulate ultracold atoms and Bose-Einstein condensates near a surface. In particular, permanent magnetic film atom chips can allow very tight confinement and intricate magnetic field designs while circumventing technical current noise. Research described in this thesis is focused on the development of a magnetic film atom chip, the production of Bose-Einstein condensates near the film surface, the characterisation of the associated magnetic potentials using rf spectroscopy of ultracold atoms and the realisation of a precision sensor based on splitting Bose-Einstein condensates in a double-well potential. The atom chip itself combines the edge of a perpendicularly magnetised GdTbFeCo film with a machined silver wire structure. A mirror magneto-optical trap collects up to 5 x 108 87Rb atoms beneath the chip surface. The current-carrying wires are then used to transfer the cloud of atoms to the magnetic film microtrap and radio frequency evaporative cooling is applied to produce Bose-Einstein condensates consisting of 1 x 105 atoms. We have identified small spatial magnetic field variations near the film surface that fragment the ultracold atom cloud. These variations originate from inhomogeneity in the film magnetisation and are characterised using a novel technique based on spatially resolved radio frequency spectroscopy of the atoms to map the magnetic field landscape over a large area. The observations agree with an analytic model for the spatial decay of random magnetic fields from the film surface. Bose-Einstein condensates in our unique potential landscape have been used as a precision sensor for potential gradients. We transfer the atoms to the central region of the chip which produces a double-well potential. A single BEC is formed far from the surface and is then dynamically split in two by moving the trap closer to the surface. After splitting, the population of atoms in each well is extremely sensitive to the asymmetry of the potential and can be used to sense tiny magnetic field gradients or changes in gravity on a small spatial scale.

•Jan 1, 2007•5 citations

Magnetic microtraps for ultracold atoms

József Fortágh, Claus Zimmermann

Trapping and manipulating ultracold atoms and degenerate quantum gases in magnetic micropotentials is reviewed. Starting with a comprehensive description of the basic concepts and fabrication techniques of microtraps together with early pioneering experiments, emphasis is placed on current experiments on degenerate quantum gases. This includes the loading of quantum gases in microtraps, coherent manipulation, and transport of condensates together with recently reported experiments on matter-wave interferometry on a chip. Theoretical approaches for describing atoms in waveguides and beam splitters are briefly summarized, and, finally, the interaction between atoms and the surface of microtraps is covered in some detail.

Reviews of Modern Physics•Feb 1, 2007•578 citations

Atom chips

R. Folman, P. Krüger, Donatella Cassettari +3 more

We report on the experimental realisation of traps and guides for neutral atoms on a nanofabricated chip. Our main results are: (a) Trap parameters with a transverse ground state size below 100 nm and frequencies of above 100 kHz (as required by QIP proposals) have been achieved. (b) We could trap and guide atoms exclusively with the fields created on the chip. (c) We have shown that a wide variety of magnetic potentials may be realised, such as quadrupole fields for a MOT, 3D minima for trapping, 2D minima for guiding, and beam splitters. (d) It has been shown that standard nanofabrication techniques and materials may he utilised to build these atom chips. The wires on the surface can stand sufficiently high current densities in vacuum and at room temperature.

•Jan 1, 2000•1 citation

Investigating the dynamics of a Bose Einstein condensate on an atom chip

I J M Barr

In this thesis I discuss work that has been carried out on the dynamics of a Bose Einstein condensate of Rb 87 produced near an atom chip. A Bose Einstein Condensate (BEC) is a quantum state of matter where a single quantum state becomes occupied by a macroscopic number of identical Bosons. In our case this is achieved by cooling a system of trapped identical rubidium 87 atoms to its ground state. To reach temperatures of condensation we initially laser cool atoms from room temperature, before loading them into a magnetic trap. The magnetic trap is produced through a combination of uniform magnetic fields from coils outside our vacuum chamber and currents running through wires on an atom chip. The atom chip is a microfabricated device, produced by a coating a silicon chip with a thin layer of gold and etching wires into it. Together, these fields create a magnetic field minimum 120μm from the surface of the chip which can be used to confine low field seeking hyperfine states of the atom in an elongated harmonic trap. Once the atoms are confined in the magnetic trap we used force evaporative cooling out to reach the phase space densities required for Bose Einstein condensation. The BEC is used to investigate the relative dynamics between the fraction of the atoms in the condensate to those not in the condensate. Our atom chip provided a suitable environment to investigate this due to fragmentation of the magnetic potential close to the chip. Small imperfections in the wires on our atom chip mean that the trapping potential isn’t smooth. Small regions of higher trapping frequency - or fragments - are formed. Due to the small size of these fragments it is possible to find a position where a condensate can form in the fragment, and see a potential of high frequency, whereas a non-condensed atom will see a lower frequency potential. We exploit this to set the condensed fraction moving relative to the non condensed part and investigate the subsequent damping of their motion relative to each other.

•May 1, 2015•2 citations

Three magnetic devices for atom optics

Philip F. Schewe

Have been demonstrated: a beam splitter, a conveyor belt, and a switch. Just as electrons drive electronics and photons drive photonics, many researchers hope that cold, neutral atoms will drive a future “atomtronics.” To process information, atoms will need to be manipulated on or near an “atom chip” using atom-based analogs of mirrors, lenses, waveguides, gratings, and other devices. The new devices reported here all exploit the interaction between a neutral atom’s magnetic moment and an external magnetic field with a gradient strong enough to create microscopic potentials. Jörg Schmiedmayer of the University of Heidelberg and his colleagues have designed a beam splitter for guided atoms, using a Y-shaped current-carrying wire nanofabricated on a surface. Depending on how current is sent through the Y, atoms can be directed to the output arms with any desired ratio. A group at the Max Planck Institute for Quantum Optics in Munich has been able to confine atom clouds in separate potential wells and transport them with 800-nm precision near a surface having time-dependent currents in a lithographically patterned conductor. The researchers have used their “magnetic conveyor belt” to merge separate clouds; their evidence shows that the process is adiabatic and can be reversed to coherently split wavepackets. Also using lithography, and following their own beam splitter, a group at the University of Colorado and NIST in Boulder has devised a switch that can direct a guided beam of neutral atoms to either of two output ports separated by 8 mm. Both the incoming and outgoing atoms are guided between two parallel wires having current flowing in the same direction. In the switch region, the atoms are guided alongside two wires with oppositely flowing current. (D. Cassettari et al., Phys. Rev. Lett. 85, 5483, 2000 http://dx.doi.org/10.1103/PhysRevLett.85.5483 . W. Hänsel et al., Phys. Rev. Lett. 86, 608, 2001 http://dx.doi.org/10.1103/PhysRevLett.86.608 . D. Müller et al., Opt. Lett. 25, 1382, 2000 http://dx.doi.org/10.1364/OL.25.001382 ; D. Müller et al., Phys. Rev. A , in press.)© 2001 American Institute of Physics.

Physics Today•Feb 1, 2001•0 citations
The article reviews briefly the rapidly evolving field of so-called atom chips for neutral atoms. Emphasis is placed on magnetic microtraps – on-chip Ioffe-Prichard and dimple trap issue is covered in some detail. The experimental setup for cooling and trapping 87Rb atoms is also presented together with some early results of on-chip magnetic trapping. Full Text: PDF References J. Schmiedmayer, "Guiding and trapping a neutral atom on a wire", Phys. Rev. A 52, R13 (1995). CrossRef M. H. Anderson, J. R. Ensher, M. R. Matthews, C. E. Wieman, and E. A. Cornell, "Observation of Bose-Einstein Condensation in a Dilute Atomic Vapor", Science 269, 198 (1995). CrossRef K. B. Davis, M.-O. Mewes, M. R. Andrews, N. J. van Druten, D. S. Durfee, D. M. Kurn et al., "Bose-Einstein Condensation in a Gas of Sodium Atoms", Phys. Rev. Lett. 75, 3969 (1995). CrossRef J. D. Weinstein, K. G. Libbrecht, "Microscopic magnetic traps for neutral atoms", Phys. Rev. A 52, 4004 (1995). CrossRef D. Müller, D. Z. Anderson, R. J. Grow, P. D. D. Schwindt, and E. A. Cornell, "Guiding Neutral Atoms Around Curves with Lithographically Patterned Current-Carrying Wires", Phys. Rev. Lett. 83, 5194 (1999). CrossRef N. H. Dekker, C. S. Lee, V. Lorent, J. H. Thywissen, S. P. Smith, M. Drndi et al., "Guiding Neutral Atoms on a Chip", Phys. Rev. Lett. 84, 1124 (2000). CrossRef J. Reichel, W. Hänsel, and T. W. Hänsch, "Atomic Micromanipulation with Magnetic Surface Traps", Phys. Rev. Lett. 83, 3398 (1999). CrossRef D. Cassettari, B. Hessmo, R. Folman, T. Maier, and J. Schmiedmayer, "Beam Splitter for Guided Atoms", Phys. Rev. Lett. 85, 5483 (2000). CrossRef M. A. Cirone, A. Negretti, T. Calarco, P. Krüger, J. Schmiedmayer, "A simple quantum gate with atom chips", Eur. Phys. J. D 35, 165 (2005). CrossRef W. Hänsel, P. Hommelhoff, T. W. Hänsch, and J. Reichel, "Bose–Einstein condensation on a microelectronic chip", Nature 413, 498 (2001). CrossRef H. Ott, J. Fortagh, G. Schlotterbeck, A. Grossmann, and C. Zimmermann, "Bose-Einstein Condensation in a Surface Microtrap", Phys. Rev. Lett. 87, 230401 (2001). CrossRef Y. Lin, I. Teper, C. Chin, V. Vuletić, "Impact of the Casimir-Polder Potential and Johnson Noise on Bose-Einstein Condensate Stability Near Surfaces", Phys. Rev. Lett. 92, 050404 (2004). CrossRef E. Salim, J. DeNatale, D. Farkas, K. Hudek, S. McBride, J. Michalchuk et al, "Compact, microchip-based systems for practical applications of ultracold atoms", Quantum Inf. Process. 10, 975 (2011). CrossRef S. Groth, Development, "Fabrication and Characterisation of Atom Chips", doctoral dissertation. (2006). R. Folman, P. Krüger, J. Schmiedmayer, J. Denschlag, C. Henkel, "Microscopic atom optics: From wires to an atom chip", Adv. At. Mol. Opt. Phys. 48, 263 (2002). CrossRef A. Arnold, Preparation and Manipulation of an 87Rb Bose-Einstein Condensate (University of Sussex 1999), PhD thesis. D. M. Farkas, K. M. Hudek, E. A. Salim, S. R. Segal, M. B. Squires, and D. Z. Anderson, "A compact, transportable, microchip-based system for high repetition rate production of Bose–Einstein condensates ", Appl. Phys. Lett. 96, 093102 (2010). CrossRef K. Dieckmann, R. J. C. Spreeuw, M. Weidemüller, and J. T. M. Walraven, "Two-dimensional magneto-optical trap as a source of slow atoms", Phys. Rev. A 58, 3891 (1998). CrossRef W. Petrich, M. H. Anderson, J. R. Ensher, and E. A. Cornell, "Behavior of atoms in a compressed magneto-optical trap", J. Opt. Soc. Am. B, 11, 1332 (1994). CrossRef
Atom chips are devices used to magnetically trap and manipulate ultracold atoms and Bose-Einstein condensates near a surface. In particular, permanent magnetic film atom chips can allow very tight confinement and intricate magnetic field designs while circumventing technical current noise. Research described in this thesis is focused on the development of a magnetic film atom chip, the production of Bose-Einstein condensates near the film surface, the characterisation of the associated magnetic potentials using rf spectroscopy of ultracold atoms and the realisation of a precision sensor based on splitting Bose-Einstein condensates in a double-well potential. The atom chip itself combines the edge of a perpendicularly magnetised GdTbFeCo film with a machined silver wire structure. A mirror magneto-optical trap collects up to 5 x 108 87Rb atoms beneath the chip surface. The current-carrying wires are then used to transfer the cloud of atoms to the magnetic film microtrap and radio frequency evaporative cooling is applied to produce Bose-Einstein condensates consisting of 1 x 105 atoms. We have identified small spatial magnetic field variations near the film surface that fragment the ultracold atom cloud. These variations originate from inhomogeneity in the film magnetisation and are characterised using a novel technique based on spatially resolved radio frequency spectroscopy of the atoms to map the magnetic field landscape over a large area. The observations agree with an analytic model for the spatial decay of random magnetic fields from the film surface. Bose-Einstein condensates in our unique potential landscape have been used as a precision sensor for potential gradients. We transfer the atoms to the central region of the chip which produces a double-well potential. A single BEC is formed far from the surface and is then dynamically split in two by moving the trap closer to the surface. After splitting, the population of atoms in each well is extremely sensitive to the asymmetry of the potential and can be used to sense tiny magnetic field gradients or changes in gravity on a small spatial scale.
Trapping and manipulating ultracold atoms and degenerate quantum gases in magnetic micropotentials is reviewed. Starting with a comprehensive description of the basic concepts and fabrication techniques of microtraps together with early pioneering experiments, emphasis is placed on current experiments on degenerate quantum gases. This includes the loading of quantum gases in microtraps, coherent manipulation, and transport of condensates together with recently reported experiments on matter-wave interferometry on a chip. Theoretical approaches for describing atoms in waveguides and beam splitters are briefly summarized, and, finally, the interaction between atoms and the surface of microtraps is covered in some detail.
We report on the experimental realisation of traps and guides for neutral atoms on a nanofabricated chip. Our main results are: (a) Trap parameters with a transverse ground state size below 100 nm and frequencies of above 100 kHz (as required by QIP proposals) have been achieved. (b) We could trap and guide atoms exclusively with the fields created on the chip. (c) We have shown that a wide variety of magnetic potentials may be realised, such as quadrupole fields for a MOT, 3D minima for trapping, 2D minima for guiding, and beam splitters. (d) It has been shown that standard nanofabrication techniques and materials may he utilised to build these atom chips. The wires on the surface can stand sufficiently high current densities in vacuum and at room temperature.
In this thesis I discuss work that has been carried out on the dynamics of a Bose Einstein condensate of Rb 87 produced near an atom chip. A Bose Einstein Condensate (BEC) is a quantum state of matter where a single quantum state becomes occupied by a macroscopic number of identical Bosons. In our case this is achieved by cooling a system of trapped identical rubidium 87 atoms to its ground state. To reach temperatures of condensation we initially laser cool atoms from room temperature, before loading them into a magnetic trap. The magnetic trap is produced through a combination of uniform magnetic fields from coils outside our vacuum chamber and currents running through wires on an atom chip. The atom chip is a microfabricated device, produced by a coating a silicon chip with a thin layer of gold and etching wires into it. Together, these fields create a magnetic field minimum 120μm from the surface of the chip which can be used to confine low field seeking hyperfine states of the atom in an elongated harmonic trap. Once the atoms are confined in the magnetic trap we used force evaporative cooling out to reach the phase space densities required for Bose Einstein condensation. The BEC is used to investigate the relative dynamics between the fraction of the atoms in the condensate to those not in the condensate. Our atom chip provided a suitable environment to investigate this due to fragmentation of the magnetic potential close to the chip. Small imperfections in the wires on our atom chip mean that the trapping potential isn’t smooth. Small regions of higher trapping frequency - or fragments - are formed. Due to the small size of these fragments it is possible to find a position where a condensate can form in the fragment, and see a potential of high frequency, whereas a non-condensed atom will see a lower frequency potential. We exploit this to set the condensed fraction moving relative to the non condensed part and investigate the subsequent damping of their motion relative to each other.
Have been demonstrated: a beam splitter, a conveyor belt, and a switch. Just as electrons drive electronics and photons drive photonics, many researchers hope that cold, neutral atoms will drive a future “atomtronics.” To process information, atoms will need to be manipulated on or near an “atom chip” using atom-based analogs of mirrors, lenses, waveguides, gratings, and other devices. The new devices reported here all exploit the interaction between a neutral atom’s magnetic moment and an external magnetic field with a gradient strong enough to create microscopic potentials. Jörg Schmiedmayer of the University of Heidelberg and his colleagues have designed a beam splitter for guided atoms, using a Y-shaped current-carrying wire nanofabricated on a surface. Depending on how current is sent through the Y, atoms can be directed to the output arms with any desired ratio. A group at the Max Planck Institute for Quantum Optics in Munich has been able to confine atom clouds in separate potential wells and transport them with 800-nm precision near a surface having time-dependent currents in a lithographically patterned conductor. The researchers have used their “magnetic conveyor belt” to merge separate clouds; their evidence shows that the process is adiabatic and can be reversed to coherently split wavepackets. Also using lithography, and following their own beam splitter, a group at the University of Colorado and NIST in Boulder has devised a switch that can direct a guided beam of neutral atoms to either of two output ports separated by 8 mm. Both the incoming and outgoing atoms are guided between two parallel wires having current flowing in the same direction. In the switch region, the atoms are guided alongside two wires with oppositely flowing current. (D. Cassettari et al., Phys. Rev. Lett. 85, 5483, 2000 http://dx.doi.org/10.1103/PhysRevLett.85.5483 . W. Hänsel et al., Phys. Rev. Lett. 86, 608, 2001 http://dx.doi.org/10.1103/PhysRevLett.86.608 . D. Müller et al., Opt. Lett. 25, 1382, 2000 http://dx.doi.org/10.1364/OL.25.001382 ; D. Müller et al., Phys. Rev. A , in press.)© 2001 American Institute of Physics.