Atomic mirror

In physics, an atomic mirror is a device which reflects neutral atoms in the similar way as the conventional mirror reflects visible light.Atomic mirrors can be made of electric fields or magnetic fields,cite journal
url=http://www.iop.org/EJ/abstract/0953-4075/39/18/002
author=H.Merimeche
coauthors=
title=Atomic beam focusing with a curved magnetic mirror
journal=JOPB
volume=39
pages=3723–3731
year=2006
doi=10.1088/0953-4075/39/18/002] electromagnetic wavescite journal
url=http://prola.aps.org/abstract/PRL/v60/i21/p2137_1
author=V. I. Balykin
coauthors=V. S. Letokhov, Yu. B. Ovchinnikov, and A. I. Sidorov.
title=Quantum-State-Selective Mirror Reflection of Atoms by Laser Light.
journal=PRL
volume=60
pages=2137–2140
year=1988
doi=10.1103/PhysRevLett.60.2137
format=subscription required] or just silicon wafer; in the last case, atoms are reflected by the attracting tails of the van der Waals attraction (see quantum reflection).cite journal
author=H.Friedrich
coauthors=G.Jacoby, C.G.Meister
journal=PRA
title=quantum reflection by Casimir–van der Waals potential tails
year=2002
volume=65
url=http://prola.aps.org/abstract/PRA/v65/i3/e032902
pages=032902
format=subscription required] cite journal
url=http://prola.aps.org/abstract/PRL/v86/i6/p987_1
author= F.Shimizu
comment=6
title=Specular Reflection of Very Slow Metastable Neon Atoms from a Solid Surface
journal=PRL
volume=86
pages=987–990
year=2001
doi=10.1103/PhysRevLett.86.987
format=subscription required] cite journal
url=http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLRAAN000071000005052901000001&idtype=cvips&gifs=yes
author=H.Oberst
coauthors=Y.Tashiro, K.Shimizu, F.Shimizu
title=Quantum reflection of He* on silicon
journal=PRA
volume=71
pages=052901
year=2005] Such reflection is efficient when the normal component of the wavenumber of the atoms is small or comparable to the effective depth of the attraction potential (roughly, the distance at which the potential becomes comparable to the kinetic energy of the atom). To reduce the normal component, most atomic mirrors are blazed at the grazing incidence.

400px|right|thumb|Ridged mirror. The wave with wavevector ">$~vec\; K~$is scattered at ridges separated by distance $~L~$At grazing incidence, the efficiency of the quantum reflection can be enhanced by a surface covered with ridges (ridged mirror).cite journal
comment=8
url=http://jpsj.ipap.jp/link?JPSJ/71/5/
author= F.Shimizu
coauthors=J. Fujita
title=Giant Quantum Reflection of Neon Atoms from a Ridged Silicon Surface
journal=Journal of the Physical Society of Japan
volume=71
pages=5–8
year=2002
doi=10.1143/JPSJ.71.5] cite journal
comment=7
url=http://annex.jsap.or.jp/OSJ/opticalreview/TOC-Lists/vol12/12e0363tx.htm
author= D.Kouznetsov
coauthors= H.Oberst
title=Reflection of Waves from a Ridged Surface and the Zeno Effect
journal=Optical Review
volume=12
pages=1605–1623
year=2005
doi=10.1007/s10043-005-0363-9] cite journal
comment=9
url=http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000094000001013203000001&idtype=cvips&gifs=yes
author= H.Oberst
coauthors=D.Kouznetsov, K.Shimizu, J.Fujita, and F. Shimizu
title=Fresnel Diffraction Mirror for an Atomic Wave
journal=PRL
volume=94
pages=013203
year=2005] cite journal
url=http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PLRAAN000072000001013617000001&idtype=cvips&gifs=yes
free=http://www.ils.uec.ac.jp/~dima/PhysRevA_72_013617.pdf
author= D.Kouznetsov
coauthors=H.Oberst
title=Scattering of waves at ridged mirrors.
journal=PRA
volume=72
pages=013617
year=2005]

The set of narrow ridges reduces the van der Waalsattraction of atoms to the surfaces and enhances the reflection. Each ridge blocks part of the wavefront, causing Fresnel diffraction.cite journal
comment=9
url=http://scitation.aip.org/getabs/servlet/GetabsServlet?prog=normal&id=PRLTAO000094000001013203000001&idtype=cvips&gifs=yes
author= H.Oberst
coauthors=D.Kouznetsov, K.Shimizu, J.Fujita, and F. Shimizu
title=Fresnel Diffraction Mirror for an Atomic Wave
journal=PRL
volume=94
pages=013203
year=2005]

Such a mirror can be interpreted in terms of the Zeno effect.cite journal
comment=7
url=http://annex.jsap.or.jp/OSJ/opticalreview/TOC-Lists/vol12/12e0363tx.htm
author= D.Kouznetsov
coauthors= H.Oberst
title=Reflection of Waves from a Ridged Surface and the Zeno Effect
journal=Optical Review
volume=12
pages=1605–1623
year=200] We may assume that the atom is "absorbed" or "measured" at the ridges. Frequent measuring (narrowly-spaced ridges) suppresses the transition of the particle to the half-space with absorbers, causing specular reflection. At large separation $~L~$ between thinridges, the reflectivity of the ridged mirror is determined by dimensionless momentum $~p=sqrt\{KL~\}~\; heta~$ ,and does not depend on the origin of the wave; therefore, it is suitable for reflection of atoms.

Applications

*Atomic interferometry
*Atom holography (see also atom laser) This was demonstrated by Shimizu and Fujita in 2002.cite journal
title = Reflection-Type Hologram for Atoms
author = Shimizu
coauthors=J.Fujita
journal = PRL
volume = 88
number = 12
pages = 123201
numpages = 4
year = 2002
comment=9
month = Mar
url=http://prola.aps.org/abstract/PRL/v88/i12/e123201
doi = 10.1103/PhysRevLett.88.123201
publisher = American Physical Society
format = subscription required]
*Atomic nanoscope cite journal
url=http://stacks.iop.org/0953-4075/39/1605
author= D.Kouznetsov
coauthors=H. Oberst, K. Shimizu, A. Neumann, Y. Kuznetsova, J.-F. Bisson, K. Ueda, S. R. J. Brueck
title=Ridged atomic mirrors and atomic nanoscope
journal=JOPB
volume=39
pages=1605–1623
year=2006
doi=10.1088/0953-4075/39/7/005] [Atom Optics and Helium Atom Microscopy. Cambridge University, http://www-sp.phy.cam.ac.uk/research/mirror.php3]

ee also

*Quantum reflection
*Ridged mirror
*Zeno effect
*Atomic nanoscope
*Atom laser

References