SciPost Submission Page

A scanning quantum cryogenic atom microscope at 6 K

by Stephen F. Taylor, Fan Yang, Brandon A. Freudenstein, Benjamin L. Lev

This is not the current version.

Submission summary

As Contributors: Benjamin Lev · Stephen Taylor · Fan Yang
Arxiv Link: https://arxiv.org/abs/2010.03559v1 (pdf)
Date submitted: 2020-10-08 18:58
Submitted by: Lev, Benjamin
Submitted to: SciPost Physics
Academic field: Physics
Specialties:
  • Atomic, Molecular and Optical Physics - Experiment
  • Condensed Matter Physics - Experiment
  • Quantum Physics
Approach: Experimental

Abstract

The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) is a quantum sensor in which a quasi-1D quantum gas images electromagnetic fields emitted from a nearby sample. We report improvements to the microscope. Cryogen usage is reduced by replacing the liquid cryostat with a closed-cycle system and modified cold finger, and cryogenic cooling is enhanced by adding a radiation shield. The minimum accessible sample temperature is reduced from 35 K to 5.8 K while maintaining low sample vibrations. A new sample mount is easier to exchange, and quantum gas preparation is streamlined.

Current status:
Has been resubmitted


Submission & Refereeing History


Reports on this Submission

Anonymous Report 1 on 2020-12-15 (Invited Report)

  • Cite as: Anonymous, Report on arXiv:2010.03559v1, delivered 2020-12-15, doi: 10.21468/SciPost.Report.2238

Strengths

1) The paper gives technical details for an upgraded scanning quantum cryogenic atom microscope. The potential (future) applications of this system are exciting and very interesting.

2) The paper is well written and contains good figures and graphs.

Weaknesses

1) The paper reports only technical improvements - without a direct demonstration how these changes impact on the performance of the system in its intended use. I.e. it would be beneficial to show an application of the improved device, an image of the atom cloud after interacting with a test surface or similar.

2) The only direct / quantitative evidence for improved operation are the lower sample temperatures, and the reduced vibrations.

4) In many places the paper refers to other publications for details. It would improve the readability to repeat at least some of these parameters.

Report

The system that is described in this paper is exciting and an impressive technical achievement. The operation of the SQCRAMscope’s and its features have been demonstrated in Ref.[4] , but this previous version only reached 35K.

The focus of this paper are the technical improvements of the system that now allow a sample temperature of 6K to be reached. These include the use of a closed cycle cryostat, which reduces vibrations and He consumption, a new sample mount, a modified cold finger and an improved cold atom gas preparation procedure.
The reduction of vibration in the system has been measured using an optical interferometer.
The publication of these technical parameters is important as other groups might benefit from the presented solutions.

However, the paper would benefit from a more clearly demonstrated improved performance in the actual task of the system. I.e. after following the lower temperature, lower vibrations, larger atom ensembles etc., it would be interesting to see, what the combined resulting impact of these improvements on a measurement target is.
In some places the paper refers to earlier publications for details, it improve readability to repeat at least some of those.

Requested changes

1) If possible add a measurement result of the improved quantum gas microscope OR add a discussion section how the changes are expected to affect the quantum gas microscope measurements and why a direct demonstration is not possible at this point.

Additional minor points:

2) Indicate confidence intervals or precision wherever possible (e.g. for measured temperatures or dimensions of wires on the chip)

3) Give more details on how the heat-sinking of the chip mount has been improved, since this seems to be an important change.

4) Page 10 "Loading efficiency is roughly the same..." How many atoms are loaded into the magnetic trap?

5) Page 10 "...bring the atoms closer to the surface." How close are the atoms to the surface?

  • validity: good
  • significance: good
  • originality: good
  • clarity: high
  • formatting: perfect
  • grammar: perfect

Anonymous Report 2 on 2020-12-9 (Invited Report)

  • Cite as: Anonymous, Report on arXiv:2010.03559v1, delivered 2020-12-09, doi: 10.21468/SciPost.Report.2273

Strengths

(1) A detailed description of the large number of improvements done to achive this new versatile magnetic field sensing machine

Weaknesses

It would have been great so see what the instrument is now capable to do. Showing how much improvement was achieved.

Report

This is a very technical paper, describing significant improvements to a unique instrument, bringing it to a point where it can be used for many different and diverse physics problems

The Scanning Quantum Cryogenic Atom Microscope (SQCRAMscope) uses ultracold BEC of atoms to sense minute magnetic fields. It was a long journey from the original demonstration (Wildermuth et al. Nature ... ) to the present state of the art as presented in this paper. With the significant improvements in this new machine a 1 dimensional arrangement of a atomic quantum gas can now be scanned as a sensor over a large 3x5 mm^2 area and positioned µm above the surface.

The description of the different methods applied is very detailed, and sometimes even feels like an instructions to build a similar instrument.

Requested changes

the references are very self centred
it would be good to have the original papers demonstrating the method used in the SQCRAMscope

Bose-Einstein condensates - Microscopic magnetic-field imaging S. Wildermuth et al. Nature 435, 440 (2005),

and its first physics application:

Long-Range Order in Electronic Transport through Disordered Metal Films
S. AIGNER, et al. Science 319, 1226 (2008),

  • validity: high
  • significance: top
  • originality: high
  • clarity: top
  • formatting: excellent
  • grammar: excellent

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