Low Noise Single Electron Source

1. Low NoiseSingle Electron Source Jin Zhang , Yury Sherkunov, Nicholas d’Ambrumenil, Boris Muzykantskii University of Warwick, U.K. Conference on Computational Physics 2009, Kaohsiung, 16th, Dec.

2. Single Electron Excitation Arbitrary Pulse:

3. Single Electron Excitation Minimal Excitation States (MES): Ivanov Lee Levitov, Phys. Rev. B 56, 6839 Keeling Klich Levitov, Phys. Rev. Lett. 97, 116403

4. Noise Characterization D 0 t D Partition Noise: Thermal Noise: D Equilibrium Noise (T=0):

5. Noise Minimization D Minimized by setting Low temperature -- mK High frequency -- GHz for abrupt opening at GHz D ? D 0 0 t t

6. Suppression of the Equilibrium Noise 1. Single Lorentzianpulse to the barrier 2. Double Lorentzian pulses to the barrier When 0.8

7. Low Noise Single Electron Source Total noise from single electron emission: Probability Distribution: Suppressed multiple electron emission High yield single electron emission JZ YS NdA BM Phys. Rev. B 80, 245308 Phys. Rev. B 80, 041313 (R)

8. Conclusion • Suppressing the quantum equilibrium noise at low temperature by tuning the tunneling barrier (QPC) transparency • Low noise on-demand single electron source at low temperature Many thanks for your attention!

9. Single Electron Source Fèveet.al, Science 316,1169 Working Condition: GHz, mK Averaged over millions of events Too Noisy Minimize the Noise? Keeling et.al, PRL 101, 196404

10. Optimal Electronic Entangler Apply Single Lorentzianpulse to the barrier 50% Entanglement efficiency, Theoretical maximum “useful”, Not “useful” No excessive not “useful” noise at all

11. Theory ofFull Counting Statistics (I) Characteristic Function Current, Noise, etc... Understood with density matrix of outgoing states:

12. Theory ofFull Counting Statistics (II) Abanovet.al 2008

13. Non Optimal Pulses For finite cut-off, additional noises are induced