Low Noise On-demand Single Electron Source
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Low Noise On-demand Single Electron Source Jin Zhang, Y. Sherkunov, N. d'Ambrumenil, B. Muzykantskii Department of Physics, University of Warwick, Coventry, CV4 7AL, U.K . (See poster by Y. Sherkunov also) ABSTRACT We obtain the full counting statistics (FCS) of a quantum point contact (QPC) for the case when the contact transparency is modulated in time, which is shown to be equivalent to a system with a time-dependent bias voltage applied between the leads. We demonstrate an improved contact opening schemes with the logarithmically divergent equilibrium noise suppressed, which can be used as an on-demand single electron source. The effect of a possible deviation of the opening is also presented. Noise Characterization Non-Quantized Opening References: [1] JZ, YS, NdA, BM, arXiv:0909.3427 [2] YS, JZ, NdA, BM, Phys. Rev. B 80, 041313(R) (2009) [3] Abanov and Ivanov, Phys. Rev. Lett. 100, 086602 (2008) [4] Keeling, Klich, Levitov, Phys. Rev. Lett. 97, 116403 (2006) [5] Ivanov, Lee, Levitov, Phys. Rev. B 56, 6839 (1997) j n j i j j n Q e n n , ) 1 ( ) ( 1 , ) 1 ( ) ( j i j j n Q e n n j n Particle: Hole: 2 1 0 0 Im ) ( i t t i t t i t i t t A : 1 1 2 : 1 2 ) ' ( 2 2 2 ' ' ' ) 1 ( ' - i in in e B ABA A A n n dtdt Q R L t i t i R L a a t S t B e t A e t A t B b b ) ( ) ( ) ( ) ( ) ( ) ( ) ( Transmission amplitude: A(t) Scattering Matrix: Noise: 2 2 2 1 A A sh Q f Tt A th Q 2 2 ) log(t F f 2 2 A eq Q Zero Temperature Equilibrium Noise: Shot Noise: Thermal Noise: 0.25 generated by an MES with w.r.t. temperature (T) fferent cut-off : 2 1 2 A t dt t V e t 0 ' ) ' ( ) ( Faraday Flux: Full Counting Statistics () in n n Pe Characteristic Function Current, Noise, etc... 0 ln ( ) m m m Q i Density matrix of the incoming states: 0 ' 1 2 i t t i a a n L L in Density matrix of the outgoing states: ) ' ( ) ' , ( ) ( ) ' ( ) ' , ( ) ( t B t t n t B t A t t n t A b b n in R in L R R out R j j i n i Q i n e e e j ) 1 ( 1 ) ( 2 (1 ) j j j Q n n eq Q th Q sh Q Q 2 2 2 2 Classify Noise as: Diagonali ze ,.. 2 , 1 , : j n n j out R Open the barrier as f t Measurement time: F Minimal Excitation States (MES) F k F k 2 2 2 () Vt t Lorentzian Pulse (L.P.) () i t t i e t i t dt t V t ' ) ' ( ) ( 0 2 / ) ( F a e h i t i Faraday Flux: F k F k Arbitrary Pulse ) ( ) ( t V t V Arb Noise Minimization for QPC? ), ε log(t F f 2 eq Q Arbitrary Switching: Low Noise Single Electron Source 1 1 1 1 1 1 1 1 2 2 2 2 Im ) ( i t t i t t i t t i t t t A 1 1 1 1 ( ) 0.8, 2 2 t Turn on QPC as: 1 ) 0 ( 4 1 2 A eq Q Probability distribution at : Total noise due to an MES: 0 A t f t Noise diverges logarithmically: 0 0 t 76 . 0 1 P Suppressed double electron emission: 51 . 0 1 P Hi-yield single electron emission:
description
Low Noise On-demand Single Electron Source Jin Zhang, Y. Sherkunov, N. d'Ambrumenil, B. Muzykantskii Department of Physics, University of Warwick, Coventry, CV4 7AL, U.K . (See poster by Y. Sherkunov also). A. 0. t. ABSTRACT - PowerPoint PPT Presentation
Transcript of Low Noise On-demand Single Electron Source
Low Noise On-demand Single Electron SourceJin Zhang, Y. Sherkunov, N. d'Ambrumenil, B. Muzykantskii
Department of Physics, University of Warwick, Coventry, CV4 7AL, U.K.(See poster by Y. Sherkunov also)
ABSTRACTWe obtain the full counting statistics (FCS) of a quantum point contact (QPC) for the case when the contact transparency is modulated in time, which is shown to be equivalent to a system with a time-dependent bias voltage applied between the leads. We demonstrate an improved contact opening schemes with the logarithmically divergent equilibrium noise suppressed, which can be used as an on-demand single electron source. The effect of a possible deviation of the opening is also presented.
Noise Characterization
Non-Quantized Opening
References:[1] JZ, YS, NdA, BM, arXiv:0909.3427[2] YS, JZ, NdA, BM, Phys. Rev. B 80, 041313(R) (2009)[3] Abanov and Ivanov, Phys. Rev. Lett. 100, 086602 (2008)[4] Keeling, Klich, Levitov, Phys. Rev. Lett. 97, 116403 (2006)[5] Ivanov, Lee, Levitov, Phys. Rev. B 56, 6839 (1997)
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