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Operating high sensitivity measurement apparata out of equilibrium Operating high sensitivity measurement apparata out of equilibrium

Operating high sensitivity measurement apparata out of equilibrium - PowerPoint Presentation

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Operating high sensitivity measurement apparata out of equilibrium - PPT Presentation

Igor Neri with Miquel LopezSuarez and Luca Gammaitoni GRAvitational waves Scienceamptechnology Symposium GRASS 2019 1718 October 2019 Equilibrium vs Outofequilibrium Most of ID: 791460

gravitational 2019 equilibrium feedback 2019 gravitational feedback equilibrium cooling waves grass symposium technology amp science october igor neri quantum

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Slide1

Operating high sensitivity measurement apparata out of equilibrium

Igor Neri

with

Miquel Lopez-Suarez

and Luca Gammaitoni

GRAvitational

-waves

Science&technology

Symposium (GRASS 2019) 17-18 October 2019

Slide2

Equilibrium vs Out-of-equilibrium

Most of the noise studies, as well as the operational condition of high sensitivity measurements

apparatus (e.g. the G.W. interferometers), are considered under the assumption that the entire system is time quasi-stationary and at thermal equilibrium.

This is true even if some of the estimations for some fundamental noises, like thermal noise, have been derived by assuming the validity of fluctuation-dissipation relations that represent the base for non-equilibrium statistical mechanics.

A question arises about the possibility to operate such measurement apparata far from equilibrium or in markedly non stationary conditions.

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Slide3

Equilibrium vs Out-of-equilibrium

Previous attempts have been carried out through the application of some clever

external feedback that could modify the apparatus dynamics in order to reduce the system response to noise, in desired frequency ranges.

See e.g.

The reduction in the

brownian motion of electrometers, Milatz J M W and van Zolingen J J 1953

Physica 19 181

Regulation of a microcantilever response by force feedback, Mertz J

et al.

1993 Appl. Phys. Lett. 62 2344

Full mechanical characterization of a cold damped mirror, M.

Pinard

,

et al.

Phys. Rev. A 63, 013808, 2000

Optomechanical scheme for the detection of weak impulsive forces, David Vitali, Stefano Mancini, and Paolo Tombesi, Phys. Rev. A 64, 051401(R) 2001; Erratum Phys. Rev. A 69, 049904 (2004)Feedback Cooling of the Normal Modes of a Massive Electromechanical System to Submillikelvin Temperature, Vinante A et al 2008 Phys. Rev. Lett. 101 033601Observation of a kilogram-scale oscillator near its quantum ground state, LIGO Collab. 2009 New J. Phys. 11 073032.Measurement-based control of a mechanical oscillator at its thermal decoherence rate, Wilson D J et al 2015 Nature 524 325Nonequilibrium Steady-State Fluctuations in Actively Cooled Resonators M. Bonaldi, et al, PRL. 103, 010601 2009RareNoise: non-equilibrium effects in detectors of gravitational waves L Conti, M Bonaldi, and L Rondoni; 2010 Class. Quantum Grav. 27 084032

GRAvitational

-waves

Science&technology

Symposium (GRASS 2019) 17-18 October 2019

Slide4

Equilibrium vs Out-of-equilibrium

An interesting contribution from

Minimum Requirements for Feedback Enhanced Force Sensing

, Glen I. Harris, David L.

McAuslan, Thomas M. Stace, Andrew C. Doherty, and Warwick P. Bowen, Phys. Rev. Lett. 111, 103603 –2013

However, two important conditions have to be met:

The system is linear

The transfer characteristic is precisely known

That showed that if the measurement apparatus is linearly coupled to the noise and to the signal, then there exists a

real-time estimation strategy

that reproduces the same measurement record as any arbitrary feedback protocol. In this case any active cooling, stationary or not,

does not improve sensitivity over properly chosen data analysis

.

In all other cases there might be an advantage

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Slide5

Cooling via electrostatic feedback in a simple interferometer

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Si

3

N

4

membrane (30 nm, 5x5 mm)

5

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Slide6

Cooling via electrostatic feedback in a simple interferometer

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Si

3

N

4

membrane (30 nm, 5x5 mm)

6

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Slide7

Cooling via electrostatic feedback in a simple interferometer

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Slide8

Cooling via electrostatic feedback in a simple interferometer

 Q = 1.7 10

5

τ

f

= 0.045 s and τ

r

= 0.707 s

Cooling phase

Recovery phase

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Slide9

Cooling via electrostatic feedback in a simple interferometer

Signal injected

With signal injected

Without

signal injected

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Slide10

Cooling via electrostatic feedback in a simple interferometer

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

T

C

= cycle duration,

t

f

= feedback duration, Duty cycle = 1 –

t

f

/T

C

Time

Cooling

(blind)

Recovering

(measuring)

Noise

Slide11

Cooling via electrostatic feedback in a simple interferometer

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

T

C

= cycle duration,

t

f

= feedback duration, Duty cycle = 1 –

t

f

/T

C

Time

Cooling

(blind)

Recovering

(measuring)

D 75%

Noise

Slide12

Cooling via electrostatic feedback in a simple interferometer

GRAvitational

-waves Science&technology

Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity 35.15 (2018): 155018.

T

C

= cycle duration,

t

f

= feedback duration, Duty cycle = 1 –

t

f

/T

C

Time

Noise

Cooling

(blind)

Recovering

(measuring)

Steady state

D

75%

Slide13

Cooling via electrostatic feedback in a simple interferometer

GRAvitational

-waves Science&technology

Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity 35.15 (2018): 155018.

T

C

= cycle duration,

t

f

= feedback duration, Duty cycle = 1 –

t

f

/T

C

Time

Noise

Cooling

(blind)

Recovering

(measuring)

D

5

0%

Steady state

Slide14

Cooling via electrostatic feedback in a simple interferometer

T

C

= cycle duration, t

f = feedback duration, Duty cycle = 1 – tf/TC

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Neri, Igor, Miquel López-Suárez, and Luca Gammaitoni. "Operating gravitational wave detectors far from equilibrium." 

Classical and Quantum Gravity

 35.15 (2018): 155018.

Slide15

Conclusions

1

Periodic cooling via feedback control is possible and under certain circumstances is capable of improving the signal to noise ratio for transient signals.

2

It is of no special use if the system is

linear and

the transfer characteristic is well known. In any other case there might be an advantage, depending on the relaxation time of the system and on the time scale of the signals to be detected.

3 (further work)

In the case of marked non-linearity there might be an advantage due to energy transfer between different frequency regions.

GRAvitational-waves Science&technology Symposium (GRASS 2019) 17-18 October 2019

Slide16

Thank you for your attention!

igor.neri@nipslab.org