Corso di laurea magistrale in Fisica

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1 Coso di laua magisal in Fisica Laboaoio di Fisica I Anonio Sasso Dipaimno di Scinz Fisich Univsià di Napoli Fdico II sasso@na.infn.i i spimno di Millikan con singol micopaicll oicamn inappola

2 spimno di Millikan mx && γ v mg soluzion sazionaia v ρg 9 η 9 η ρ g L v L 0 d soluzion sazionaia γ v S mg q d q 6 πη v L v S di vido da: hp://

3 spimno di Millikan ivisiao con singol micosf inappola oicamn F F op l k Δx q q

1pN < nm fw nm fw nm Micopip Aspiaion 0.

4 Singlpaicl Manipulaion Tchniqus Aomic Foc Micoscop Opical Twzs Magnic Twzs las bam objciv F xnal magns F ap F xnal magnic bad focus of opical ap opical ap foc balancs h xnal foc sufac DNA Foc ang : 10pN 10nN 10fN 00 pn 10 nn 100 nn Foc snsiiviy: Spaial soluion: 1pN 0.0pN 0.1pN < nm fw nm fw nm Micopip Aspiaion 0.01 nn 1000 pn Anibodyanign Acinacin Bioinavidin Bioinspavidin 0pN 110pN 160pN 60pN

Pion of opical apping: Ahu Ashkin 1969/70:

5 Pion of opical apping: Ahu Ashkin 1969/70: A. Ashkin,.L. Lokhov suggs o mploy adiaion pssu fo manipulaion wih aoms, molculs and micopaicls 1986: A. Ashkin singl bam opical ap Opical wzs 1987: A. Ashkin opical wzs movs wih bacia and viuss wihou hi damag C B

lviaion Nual dilcic paicls siz: 0nm00μm foc: 10

6 Opical Twzs A. Ashkin Op. L. 11, 1986 Opical apping Tapping obsva Opical lviaion Nual dilcic paicls siz: 0nm00μm foc: pn Biological maials: vius, bacia, clls, molcula moos, biological bonds,

7 Mchanical ffcs of ligh Ligh cais: ngy hν Tmpau ha o cu Lina momnum hν p c Focs mov o ap Angula momnum l ±h Toqus oa o wis

8 Bsids ngy ligh cais: lina momnum m m focs Johanns Kpl Gman 1571 sola wind Classical picu M hoy Maxwll 1mW 1pN adiaion pssu Quanum picu phoon momnum angulag momnum oqus p hνν c Wih h advn of lass: Las cooling Bosinsin Condnsaion Opical Twzs

9 Sola adiom by W. Cooks, 1974 P hνν c P hν c

10 Lbdv s xpimn 1901 spcchio fascio luminoso filo di quazo

11 adius of h paicl much small ha h ayligh gim a<<λ adius of h paicl much small ha h apping wavlngh 0 λ a < Inducd dipol m 1 a n m m a n p,, 1 4, 3 0 α ε π n n 1 Sc in f c dissip i p F 1 n n m polaizabiliy Scaing foc dissipaiv T T p sca S m m a k c n S C c n F π m c c 3 Gadin foc consvaiv : im avagd Poyning vco T S Gadin foc consvaiv T x T gad gad m m a n F F 3 0, 1, ε π T, α

12 Sn Glach xpimn

13 Mi gim a>>λ Gomical opics appoximaion Momnum chang Momnum chang in ou Foc ou Δ Δ in Bigh ay Dim ay Laal foc dp F d Axial foc

14 Singl ay soluion F sca fom Fsnl fomula F gad [ ] ] F n P T cosθ cos θ 1 cos θ sca c 1 cos [ sinθ sin ] F n P T sin θ gad c 1 cos θ A. Ashkin, Biophys. J. 61, 199

15 Basic ida: Gadin opical fild a b di appl dal sio hp://ph.coloado.du/

16 3D Opical ap: Gaussian mod Opical axis Wav fon Scaing foc Gadin foc Colloidal paicl Focusd las bam I I zxp[ x y / w z ] I 0 I z b 1 z / b πw 0 λ

17 Basic Schm of Opical Twzs Gaussian High NA objcivs las bam Ovfilling n 1 >n I F gad >F sca 50 μm 3D ap Tapping fficincy: i Q Q foc oc momnum p sc F Pn / c

18 Opical Twzs sup 1μm vino 50μm acqua spac Piano focal olio vino las Gaussian las bam

19 Snso posiion I: Quadan Phoodiod X Q1 Q Q3 Q4 1 Q1 Q Q3 Q4 34 Y Q1 Q3 Q Q4 Q1 Q Q3 Q4 Z Q1 Q Q3 Q4 6 4 z 1 fom h slop h calibaion faco β [nm/vol] is found! Sign nal Sgnal dl foodiodo a quadani Posiion µm 1 yab*x a 0.06±0.03 b ±0.000 /nm β 173 ± Posizion nm 6 nm / Δxβ Lina spons small Dx Typical snsiiviy: 3 nm!! Typicali l bandwidh: khzmhz

20 Polysynbad capu φ1 mm Yas cll Tim shaing aps by galvo mios

21 Scoisch danc is cub

22 Tacking of opically appd paicls QP x y z x Fkx K: ap siffnss Langvin q. ovdampd haminic oscillao m && x γ x& κ x F Fo micomic paicls in wa inial is ngligibl

23 1.quipaiion mhod x man squa displacmn man squa volag 1 k B T 1 κ x 1 κβ x 0 x β

24 .Bolzmann saisics Pobabiliy of finding a small paicl in a ponial x in a volum dx is don by Bolzmann saisics x p x dx C xp k B T 1 x k B T ln p x k B T ln C κ x 1 κβ x offs offs px is don by h hisogam of im cod of sph posiions k is obaind fom h paabolic fi Xaxis Yaxis vn hs mhods nd calibaion of h posiion snso β bu do no nd infomaion abou h sph siz and mdium viscosiy

25 3. Pow Spcal Dnsiy fquncy domain quazion di Langvin m && x γ x& κx F S f γπ k β B T f f c f c κ 1 πγ c loglog lina A.Buosciolo al. Op.Commun

26 4. Auocolaion mhod f B B c c k T k k T k c π 0 k k π d f S f i 1 π d c f S c μs 108 C C This mhod dos no nd calibaion of h posiion snso bu nds infomaion abou sph siz and mdium viscosiy.

27 volag 1.Spwis gim 0 im q.oscillaoy gim volag im

28 1. Tapping in saic fild volag im

capacianc d : Doubllay sisanc i : Soluion sisanc d dpnd on: dox

29 Doubl lay lcic fild in h lcoly can b asly calculad fom an quivaln cicui: quivaln cicui quivaln ff q ff C d : Doubllay capacianc d : Doubllay sisanc i : Soluion sisanc d dpnd on: dox acions a lcods lcolys ionic concnaion 0 o 0 d max DL DL d d d d C d DL C d

30 DL d d d o 0 o 0 d 0 max 0 Z o i 0 d o d

31 ff h l h q F F F x x κ γ & ] [ max ff h q F DL 1 max γ γ γ k ff k DL l ff k q k q x DL Z o i 0 1 max OP OP DL x x x DL C d DL DL x k OP γ OP x max x

32 . Tapping in oscillaoy gim γ x& κxκ x F F h F h l q cos π f ff 0 l kbt 1 kbtγ S f δ f 4π γ f f k 3 l c f S f S f f l f C obs al.j. Chm. Phys. 16, f l k BT Psig I p f df γ k q k ff P sig No vy acua dminaion!!

33 Nomalizd auocolaion funcion 1 S f c xp iπ f d π Foc aio c 1 πf ξ c C cos π f l c0 1 ξ 1 ξ ξ q 1 ff F o l kbtk f F l h Thmal conibuio Oscill. m 1 f l 1 1 fc fc ξ <1: hmal nois ξ >1 1 : lcical modulaion

34 cos 1 π ξ π l f f c C c cos π ξ ξ l f c C C 1 ξ ξ 1 ξ c l B ff f f k T k q πγξ k Chag snsiiviy ~!!

35 Wak foc masumns ξ is masud fom ACF k T B f f l c F q πγξ l ff k If h fild is known h chag can b masud o vicvsa SN aio

36 Chag masumns Unifom lcic fild εε η μ 0 ζ ζ 15.7m Q ACF 1. ± C xp Q Z h ζ kbt a λ B 1 κa 10 xp Q Z 1.0 ± C

37 1.lcic fild masumns: Wipla gomy G.Psc al. Labonachip, in pss h150 μm molibdn wi ~ ITO lcod Φ10 μm x y z covslip C x, y, z C x, y, z hoy xp

38 3.lcic fild aound a nanomic ip h35 μm molibdn wi Φ10 μm y x ~ ITO lcod z covslip SM imag y x

39 Thoyxpimn vc xpimn h x

1 Lecture: pp

1 Lecture: pp EE334 - Wavs and Phasos Lcu: pp -35 - -6 This cous aks vyhing ha you hav bn augh in physics, mah and cicuis and uss i. Easy, only nd o know 4 quaions: 4 wks on fou quaions D ρ Gauss's Law B No Monopols