aKWISP: investigating short-distance interactions at sub-micron … · 2017-07-27 · G. Cantatore...

G. Cantatore - CdS INFN 10/7/2018

aKWISP: investigating short-distance interactions at sub-micron scales

G. Cantatore (Univ. e INFN Trieste)INFN TriesteINFN Perugia (g.c. Camerino)

aKWISP working group:V. Anastassopoulos (Univ. of Patras)G. Cantatore (Univ. and INFN Trieste)S. Cetin (Bilgi Univ.)H. Fischer (Univ. of Freiburg)W. Funk (CERN)A. Gardikiotis (Univ. of Patras)D.H.H. Hoffmann (TU Darmstadt)M. Karuza (Univ. of Rijeka and INFN Trieste)Y.K. Semertzidis (CAPP, Korea)D. Vitali (Univ. of Camerino)K. Zioutas (CERN and Univ. of Patras)S. Zippilli (Univ. of Camerino)

1


Sommario

• L’Idea

• Il progetto aKWISP

• Attività previste e richieste finanziarie

2


aKWISP idea and motivations• Idea: enter the field of Short Distance Interactions (SDI) experiments with a setup

capable of investigating distances down to O(10-100) nm totally uncovered territory

• Physical motivations: SDI give access to fundamental BSM physics

• extra dimensions

• chameleons

• scalar Dark Matter

• dilatons

• axions

• …

• Basic experimental technique in SDI:

• two masses: “source” mass and“sensing” mass

• excite the “source” ⇒ “sensing” mass gives signal = f(separation distance)

• We present aKWISP, a device able to investigate SDI at O(100 nm) or less separation distances

• start from KWISP, an opto-mechanical particle detector working at CAST (CERN)

• go beyond with advanced-KWISP (aKWISP)

• two nano-membranes in close proximity

• excite one with a pump laser, monitor the other with a sensing laser

3


aKWISP idea and motivations• Idea: enter the field of Short Distance Interactions (SDI) experiments with a setup

capable of investigating distances down to O(10-100) nm totally uncovered territory

• Physical motivations: SDI give access to fundamental BSM physics

• extra dimensions

• chameleons

• scalar Dark Matter

• dilatons

• axions

• …

• Basic experimental technique in SDI:

• two masses: “source” mass and“sensing” mass

• excite the “source” ⇒ “sensing” mass gives signal = f(separation distance)

• We present aKWISP, a device able to investigate SDI at O(100 nm) or less separation distances

• start from KWISP, an opto-mechanical particle detector working at CAST (CERN)

• go beyond with advanced-KWISP (aKWISP)

• two nano-membranes in close proximity

• excite one with a pump laser, monitor the other with a sensing laser

3

PHYSICAL REVIEW D VOLUME 30, NUMBER 1 1 JULY 1984

New macroscopic forces?

J. E. Moody' and Frank WilczekInstitute for Theoretical Physics, Uniuersity of California, Santa Barbara, California 93106

(Received 17 January 1984)

The forces mediated by spin-0 bosons are described, along with the existing experimental limits.The mass and couplings of the invisible axion are derived, followed by suggestions for experimentsto detect axions via the macroscopic forces they mediate. In particular, novel tests of the T-violating axion monopole-dipole forces are proposed.

MACROSCOPIC FORCES

Very light, weakly coupled bosons are occasionally sug-gested in the literature, for example, axions, ' familons,majorons, arions„and spin-1 antigravitons. Such parti-cles must couple very weakly to ordinary matter to haveeluded detection thus far. A boson with small enoughmass (say, 10 eV) would have a macroscopic Comptonwavelength (say, 2 cm) and would mediate a force on lab-oratory scales. Even if very weakly coupled at the single-particle level, a macroscopic body with 10 constituentscould produce a measurable, coherent light-boson field.In the familiar case of gravity, the dimensionless couplingbetween two nucleons due to graviton exchange is absurd-ly small [(m„„,&„„/Mp] g) —10 ], but two 1-g massesseparated by 1 cm experience a measurable force of

(6X10 ) (m~/Mpi) =6.7X10 dyn .(1 cm)

We shall be interested in the possibility of detectingvery light spin-0 bosons through the macroscopic forceswhich they mediate. The possible forces are determinedby the allowed couplings; the spin-0 boson must couple toan effectively conserved quantity. There are only twopossibilities for couplings to fundamental fermions: thescalar vertex and the pseudoscalar vertex. The scalar andpseudoscalar vertices can be analyzed in momentum spaceusing the Gordon decomposition. For pure spacelikemomentum transfer q, they become

scalar,

pseudoscalar,

qPgpq(qW'(pf }t YS P(p )gpq'(q} 2M P(pf )t1 s1 tb(p'}

=gptp(q} [gt(pf );&g(p;)] . (2)

Here pf——p +q/2 and p; =p —q/2 are the final and ini-tial on-shell momenta and M is the fermion mass. Thematrix X is the diagonal spin matrix. In the nonrelativis-tic limit (small fermion velocity and momentum transfer),the scalar coupling is spin-independent and depends only

~~upon the fermion density g&@pe ' q '. The pseudoscalarcoupling is entirely spin-dependent, however. The virtualboson fields of a fermion in the two cases will thus be"monopole" and "dipole" fields (in the sense of the multi-ple expansion).The scalar and pseudoscalar vertices (1) and (2) can ap-

pear in one-boson-exchange graphs in three combinations;this allows the existence of three distinct forces. Thetwo-fermion potential can be calculated in the inverseBorn approximation,

d q (vertex 1)(vertex 2)e'q''(2n. ) q +w~

The results are (see Fig. 1)

(monopole),—Nl l'—gsgse

g, tp(q)p(pf )g(p; )=gstp(q), f(pf )$(p; )

—i " "p(pf )tT~"g(p;); (1)2M

monopole-dipole,

(dipole),

rA A02r m& 1 —m r

8mM2 r r 2

1 2 VlgI'gI' ~y 1 4~ 3 Iq 3~y 3 —m rV(r) = (&,.&„),+, + 5 (r) —(&, r")(&,.r") + +— e16mMM " r2 „3 3 r2 r3 (6)

Regardless of the assigned parity of the light, spin-0 bo-son, the (monopole} and (dipole) forces conserve P andT. However, the monopole-dipole force enjoys a uniquestatus amongst possible macroscopic interactions, because

&.r violates P and T and of course macroscopic P and Tviolation has heretofore not been observed.A few experimental upper limits exist for the strength

of anomalous (monopole) and (dipole} interactions.

30 130


A scenario for aKWISP• The ATLAS experiment at LHC was able recently to explore the compactification

of extra dimensions at short distance scales stopping at 11 μm (arXiv:1604.07773 and CERN thesis at https://cds.cern.ch/record/2194414?ln=en)

• Other experiments probe Yukawa-type forces down to 10 μm ⇒ 1 μm (see for

example A. Geraci et al., PRD, D78(2), 022002 (2008))

• aKWISP could probe distance scales of O(100 nm) or less reaching atto-N or even zepto-N sensitivities ⇒ unexplored regions in the parameter space of

Yukawa-type interactions with access to chameleons, dilatons, scalar DM, axions,…

• Recent suggestions:

- Y. Semertzidis: introduce a mass gradient to activate axion-mediated short range interactions (private communication)

- F. Wilczek: go down to 10 nm separation and investigate the Casimir effect (discussion at the “Axion Dark Matter” workshop, Nordita Institute, Stockholm, 5-9 Dec. 2016)

- A. Zhitnitsky: detect axions using the Topological Casimir Effect (arXiv:1702.00012)

4

https://cds.cern.ch/record/2194414?ln=en

G. Cantatore - CdS INFN 10/7/2018 5

Projected aKWISP detection @ 3 mK with 105 s integration time = 10-20 N- black curve: 1 micron separation distance- blue curve: 100 nm separation distance

Exclusion plot taken from; A. Geraci et al., Physical Review Letters, 105(10), 101101 (2010)

produce spurious forces on the sphere. By translating theposition of the optical trap along the surface, these andother backgrounds, e.g., vibration, can be distinguishedfrom a Yukawa-type signal, as any Yukawa-type signalshould exhibit a spatial periodicity associated with thealternating density pattern, similar to the system discussedin Ref. [23].

Increasing the radius of the sphere can significantlyenhance the search for non-Newtonian effects at longerrange. Curve (b) in Fig. 3 shows the estimated search reachthat would be obtained by scaling the sphere size by afactor of 10 and positioning it at edge-to-edge separation of3:8 !m from a source mass with thickness t ¼ 10 !mconsisting of sections of width 10 !m driven at an ampli-tude of 13 !m. Such a larger sphere could be trapped in anoptical lattice potential with the incident beams at a shal-low angle, instead of in an optical cavity, to enable sub-wavelength confinement. In this case cooling could beperformed by use of active feedback. Alternatively itmay be possible to trap the larger 1:5 !m sphere in acavity by use of longer wavelength light (e.g., "trap ¼10:6 !m) by choosing a sphere material such as ZnSewith lower optical loss at this wavelength.

The experiment we have proposed may allow improve-ment by several orders of magnitude in the search for non-Newtonian gravity below the 10 !m length scale. Anexperimental challenge will be to capture and cool indi-vidual microspheres and precisely control their positionnear a surface. Previous experimental work has been suc-cessful at optically trapping 1:5 !m radius spheres [4], andsimilar techniques may work for the setup proposed here.Extrapolating the results of Ref. [7] at 10"6 Torr for the

system we consider would yield a pressure-limited Q#109. In the absence of additional damping mechanisms, weexpect that Q $ 1012 could be achieved at lower pressure.Further improvements in force sensitivity may be possiblein a cryogenic environment.We thank John Bollinger and Jeff Sherman for a careful

reading of this manuscript. A. G. and S. P. acknowledgesupport from the NRC.

*[email protected][1] A. Ashkin, Phys. Rev. Lett. 24, 156 (1970); A. Ashkin and

J.M. Dziedzic, Appl. Phys. Lett. 19, 283 (1971); A.Ashkin and J.M. Dziedzic, ibid. 28, 333 (1976).

[2] D. G. Grier, Nature (London) 424, 810 (2003).[3] K. C. Neuman and S.M. Block, Rev. Sci. Instrum. 75,

2787 (2004).[4] R. Omori, T. Kobayashi, and A. Suzuki, Opt. Lett. 22, 816

(1997); L. Mitchum and J. P. Reid, Chem. Soc. Rev. 37,756 (2008); T. Li et al., Science 328, 1673 (2010).

[5] D. E. Chang et al., Proc. Natl. Acad. Sci. U.S.A. 107, 1005(2010).

[6] O. Romero-Isart et al., New J. Phys. 12, 033015 (2010).[7] L. D. Hinkle and B. R. F. Kendall, J. Vac. Sci. Technol. A

8, 2802 (1990).[8] D. Rugar et al., Nature (London) 430, 329 (2004).[9] R. Maiwald et al., Nature Phys. 5, 551 (2009); M. Biercuk

et al., arXiv:1004.0780.[10] K. G. Libbrecht and E.D. Black, Phys. Lett. A 321, 99

(2004).[11] N. Arkani-Hamed, S. Dimopoulos, and G. Dvali, Phys.

Lett. B 429, 263 (1998).[12] S. Dimopoulos and G. F. Guidice, Phys. Lett. B 379, 105

(1996).[13] H. B. G. Casimir, Proc. K. Ned. Akad. Wet. 51, 793

(1948).[14] E. Rousseau et al., Nat. Photon. 3, 514 (2009).[15] Y. Hadjar et al., Europhys. Lett. 47, 545 (1999).[16] P. S. Epstein, Phys. Rev. 23, 710 (1924).[17] R. Kitamura, L. Pilon, and M. Jonasz, Appl. Opt. 46, 8118

(2007).[18] A. Lambrecht and S. Reynaud, Eur. Phys. J. D 8, 309

(2000).[19] H. B. G. Casimir and P. Polder, Phys. Rev. 73, 360 (1948).[20] A. Scardicchio and R. L. Jaffe, Nucl. Phys. B704, 552

(2005).[21] D.M. Harber et al., Phys. Rev. A 72, 033610 (2005).[22] P. A. Maia Neto, A. Lambrecht, and S. Reynaud,

Europhys. Lett. 69, 924 (2005).[23] A. A. Geraci et al., Phys. Rev. D 78, 022002 (2008).[24] R. S. Decca et al., Phys. Rev. D 75, 077101 (2007).[25] R. S. Decca et al., Phys. Rev. Lett. 94, 240401 (2005).[26] M. Masuda and M. Sasaki, Phys. Rev. Lett. 102, 171101

(2009).[27] S. K. Lamoreaux, Phys. Rev. Lett. 78, 5 (1997).[28] J. Chiaverini et al., Phys. Rev. Lett. 90, 151101 (2003).[29] D. J. Kapner et al., Phys. Rev. Lett. 98, 021101 (2007).[30] S. Dimopoulos and A.A. Geraci, Phys. Rev. D 68, 124021

(2003).

λ

|α|

Excluded by experiment

Yukawa messengers

dilaton

moduli

gauged B#

Geraci ‘08

Kapner ‘07

Chiaverini ‘03

Lamoreaux ‘97

Masuda ‘08

Decca ‘05

Decca ‘07

a

b

FIG. 3 (color online). Experimental constraints [23–29] andtheoretical predictions [30] for short-range forces due to aninteraction potential of Yukawa form V ¼ " GNm1m2

r %½1þ #e"r="(. Lines (a) and (b) denote the projected improvedsearch reach for microspheres of radius a ¼ 150 nm and a ¼1500 nm, respectively.

PRL 105, 101101 (2010) P HY S I CA L R EV I EW LE T T E R Sweek ending

3 SEPTEMBER 2010

101101-4

1 μm

100 nm

V = �GNm1m2

r(1 + ↵e�r/�)


advanced-KWISP in a nutshell

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• Build on KWISP core technologies (*)

• membrane-based optomechanical force sensor

• sensitivity enhanced by the combined quality factors of two resonators: mechanical (membrane) and optical (FP)

• sensitive to extremely tiny forces and sub-nuclear size displacements

• Introduce the DMIM - Double Membrane Interaction Monitor

• two membranes separated by O(100 nm)-size micropillars acting as sensing and source masses

• different Q’s and resonant frequencies

• Implement advanced technologies to achieve the ultimate sensitivity (target: 10-20 N/√Hz)

• homodyne detection

• membrane optimisation

• cryogenic cooling

• environmental noise reduction

membrane resonance

Fabry-Perot

O(100 nm)spacing

sensing laser

pump laser

DMIM - Double Membrane Interaction Monitor

(*) M. Karuza, G. Cantatore, A. Gardikiotis, D.H.H. Hoffmann, Y.K. Semertzidis, K. Zioutas, Physics of the Dark Universe, 12 (2016) 100-104


DMIM prototype design

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NORCADA Inc UPDATED APRIL 10,2017

PROPRIETARY AND CONFIDENTIAL Page 2 of 3 3D MODEL OF TWO DEVICES ASSEMBLED 10um SEPARATION

Design developed together with Norcada Inc, Canada (www.norcada.com)

frame dimensions:side10 mm, thickness 200 mmmembrane dimensions:side 5 mm, thicnkesses 30 nm and 200 nm

Confide

ntial

http://www.norcada.com


DMIM improved design

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aKWISP principle schematic

9

G. Cantatore 2016


Key aKWISP technologies

• DMIM (Double Membrane Interaction Monitor)

• Fabry-Perot resonator

• pump beam calibration


• membrane coating and customisation


• environmental noise suppression

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Key aKWISP technologies

• DMIM (Double Membrane Interaction Monitor)

• Fabry-Perot resonator

• pump beam calibration


• membrane coating and customisation


• environmental noise suppression

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Mission critical!


Low temperature operation• Cooling the membrane down to an as low as possible equivalent

temperature brings the sensitivity to the ultimate limit

• Cooling can take place in two stages

• cryogenic cooling: the physical temperature of the membrane is lowered by standard means, such as contact with a cold finger

• optical cooling: energy is transferred from thermally excited phonons in the membrane to photons in a laser beam (*)

• optical cooling can lower the equivalent temperature by a factor of 1000

• the mK range is in principle accessible starting from LHe cryo-cooling at 4 K

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(*) see for instance M. Karuza et al., New Journal of Physics, 14(9) (2012)

The thermal noise limit to a force measurement is given by

Sf =

!

4kkbT

ω0QN/

√Hz (1)

where k ≈ 30 N/m is the effective spring constant of the membrane, kb is Boltzmann’s con-

stant and T is the temperature,. At 300 K, using the measured parameters, the thermal lim-

ited force sensitivities are SF = 7×10−16 N/√

Hz while at 300 mK, Sf = 7×10−18 N/√

Hz.

Although these levels of sensitivity can be achieved with a micro- or nano-cantilever

system, the advantage of the silicon nitride membranes is that the sensitive area can approach

25 (mm)2. In addition, the membranes are flat to order 1 nm over the entire area, and have a

roughness less than 0.1 nm rms over the surface. To illustrate the experimental advantages

of these membranes, consider a measurement of the Casimir force between metal coated

surfaces. At long distances, the finite temperature correction dominates the force. If a

probe with a spherical tip of radius of curvature R is brought a distance d from a flat

surface, the force is

F =1.2RkbT

d2. (2)

Taking R = 1 cm, the signal to noise (per unit bandwidth), S/N = F/SF is unity when d =

26 µm, which is an order of magnitude larger distance for S/N = 1 in experiments employing

a torsion pendulum [3]. For micro-cantilever measurements, the S/N is about unity at

0.5 µm (at this distance, the force is approximately proportional to 1/d3 for the sphere-

plane geometry). (The conducting region on the membrane must have a diameter larger

than 2 mm for the usual sphere-plane approximation to be valid.) Measuring the Casimir

force between metal films at such a large distance would resolve a theoretical controversy

surrounding the thermal correction to this force. In this instance the flatness and smoothness

of the membrane are also of importance.

2. Research Projects in Fluids

Given that the study of the mechanical dynamics of silicon nitride membranes has begun

only recently, our proposed research project discussion is divided into two sections. First, we

propose a further study of the membranes themselves, followed by a series of experiments.

A. Membrane Resonator Studies

There are several issues to be further studied in the fabrication, mounting, and motion

detection of silicon nitride membranes. First, it is necessary to have a metallic coating on

2

from S. Lamoreaux, arXiv:0808.4000


Sensing axion-mediated forces

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no mass gradient ⇒nucleon couplingmass gradient ⇒ spin coupling

ongoing dicsussion with Y. Semertzidis

ongoing discussions with Y. Semertzidis


Detection of the Topological Casimir Effect

• A. Zhitnitsky : An additional “Casimir” pressure might appear between two parallel plates if an object with “non-trivial topology” is inserted ⇒

Topological Casimir Effect

• TCE should also depend on the intensity of a static external magnetic field in an oscillatory fashion

• We can test this prediction with a suitably designed DMIM

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Physics Beyond Colliders program at CERN

• From the PBC official mandate (http://pbc.web.cern.ch):

“Physics Beyond Colliders is an exploratory study aimed at exploiting the full scientific potential of CERN's accelerator complex and its scientific infrastructure through projects complementary to the LHC, HL-LHC …and other possible future colliders. These projects would target fundamental physics questions that are similar in spirit to those addressed by high-energy colliders, but that require different types of beams and experiments.

•aKWISP has been included in the program from the start under the technology WG

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http://pbc.web.cern.ch

http://pbc.web.cern.ch


aKWISP projected timeline•Approximate timescale : 2-3 years

•4 R&D phases

1. Preliminary installation phase ( ~6 months)

- preparation of the experimental area

- infrastructure installation (optical bench, vacuum system, instrumentation)

- optics setup and initial alignment

- beam and cavity characterisation

2. Room temperature commissioning phase (~6 months)

- DMIM studies at room temperature

- absolute sensitivity measurements with pump beam technique

- preliminary data taking

3. Low temperature preliminary phase (~12 months)

- design and construction of DMIM cooling cryostat

- setup of laser cooling optics

- cooling tests

- integration of laser and cryogenic cooling

- preliminary sensitivity tests

4. Low temperature commissioning phase (~8 months)

- DMIM insertion

- preliminary pumping and sensitivity tests

- final commissioning

- data taking

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Year 1 Year 2 Year 3

Preliminary installation

phase

Room temperature

commissioning phase

Low temperature preliminary phase Low temperature commissioning phase

6 months 6 months 12 months 8 months


Collaborazione aKWISP• Collaboratori italiani

Trieste

Camerino (INFN Perugia)

(Padova e LNL forse dal 2019)

• Collaboratori stranieri

CERN

Univ. di Friburgo

TU Darmstadt

Bilgi Univ. Istanbul

Univ. di Patrasso

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• Personale INFN 2018

G. Cantatore (RN) - TS - 0.7 FTE

M. Karuza - TS - 0.3 FTE

S. Zippilli - PG (g.c. Camerino) 0.4 FTE

Totale 2018 = 1.4 FTE


Attività prevista e richieste 2018• Durata prevista 3 anni

• Primo anno

• Acquisizione del dispositivo (realizzato su nostro progetto dalla Norcada Inc, Canada)

• Test di lettura interferometrica a temperatura ambiente

• Ricerca di un "host laboratory" che possa fornire supporto alla criogenia (contatti avviati con CERN, Canfranc e LNL)

• Secondo anno

• Progetto del sistema criogenico

• Definizione dell'host laboratory"

• Inizio test a bassa temperatura

• Terzo anno

• Test a bassa temperatura

• Misure di sensibilita'

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MissioniContatti con Camerino, CERN. LNL, Canfranc

5 kEUR

Consumo Materiale ottico 5 kEUR

Apparati Quota per acquisto DMIM 15 kEUR

Tot. 25 kEUR

OfficinaComponenti meccanici per supporti ottica

1 m. u.

ElettronicaElettronica analogica e per DAQ

1 m.u.

aKWISP: investigating short-distance interactions at sub-micron … · 2017-07-27 · G. Cantatore...

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