1 realization of qubit and electron entangler with nanotechnology emilie dupont
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Realization of qubit and electron entangler with
NanoTechnology
Realization of qubit and electron entangler with
NanoTechnology EmilieEmilie DupontDupont
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Plan
1. Quantum computing2. Realization of a QUantum
Bit.3. Why an electron entangler is
needed ?4. Experimental setup
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Quantum computing
Cryptography: perfectly secure communication.
Searching, especially algorithmic searching
Simulating quantum-mechanical systems efficiently.
Efficiency: factorising a 300 digits number in 1 sec / 150,000 years for a classical computer
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Quantum computing
A. Aspect et al, PRL 49, 1804 (‘82) A. Aspect, Nature 398, 189 ('99)
Quantum operator useful for factoring + security
Entanglement : 1 measure instantaneously know other
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Quantum Qubit
artificial atom AlGaAs heterostructure :
depleting a 2DEG inside create a quantum dot
With gate : controlling the energy level of e- in the dots
D. Berman, N. B. Zhitenev, and R. C. D. Berman, N. B. Zhitenev, and R. C. Ashoori Ashoori
Phys. Rev. Lett. Phys. Rev. Lett. 8282, 161 (1999), 161 (1999)
van der Wiel et van der Wiel et alal Rev. Mod. Phys. Rev. Mod. Phys. 7575, 1 (2003) , 1 (2003)
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Quantum Qubit
Double dots = qubit: leads on resonance + choice of gate voltage: (0,1) or (1,0)
spin qubit: 1 e- out of resonance
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Electron Entangler
Superconducting lead = source of Cooper pairs
Correlated e- on the dots but spatially separated =
EPR pairsBut noise effect
É. Dupont and K. Le Hur Phys. Rev. B É. Dupont and K. Le Hur Phys. Rev. B 7373, 045325 (2006), 045325 (2006)
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Operation on Qubit
Novel entanglement mechanisms based on the prolific combination of charge and spin qubits.
The spin entanglement can be controlled by the charge qubit. (Effect of charge noise will be neglected)
K. Le Hur, P. Recher, É. Dupont, and D. K. Le Hur, P. Recher, É. Dupont, and D. Loss Loss
Phys. Rev. Lett. Phys. Rev. Lett. 9696, 106803 (2006), 106803 (2006)
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Measurements and Experimental setup
SC + Carbon Nanotubes easier and same conclusion
Samuelson, Sukhorukov, Büttiker, PRB 61, R16303 ('00) PRB 70, 115330 ('04)
C. Bena, S. Vishveshawara, L. Balents,
M. Fisher PRL 89, 037901 ('02)
Measure of the spin state of the electron with a beam-splitter
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Conclusion
Can create an EPR pair but affected by
noise.
Can control spin entanglement by the
state of charge qubit.
Experimentaly feasible (CNT…).