Phase-slip Oscillator
Alina M. Hriscu, Yuli V. Nazarov
Kavli Institute for Nanoscience, TU Delft
Acknowledgements:
Hans Mooij, Kees Harmans,
Ad Verbruggen, Tomoko Fuse
Delft
University of
Technology
Challenge the future
(quantum) Phase-slips
Introduction
• Thermally-activated phase-slips
• 2p slip of the phase => "phase-slip“
Mooij and Harmans (2005)
time
• Superconducting wires : d≈10 nm
• resistance below Tc
• Quantum phase-slips
• proposed for qu-bit
• coherent!
• not experimentally confirmed yet
• Our idea: other means of sensitive
measurements?
Schön (2000)
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Phase-slip oscillator
Damped LC oscillator + phase-slip wire
Γ : OSCILLATOR QUALITY
ES≠0
=0
n=…
n=1
n=0
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Unusual non-linearities
• Correction to the energy levels
phase-slip amplitude
charge
Gate voltage sensitivity
Unusual non-linearities
• More interesting problem
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Intermezzo: Non-linearities
Duffing oscillator
Usual
n
2
Resonance spectrum
Non-linearities
Phase-slip oscillator
Unusual
p
cos(2 n  )
4
ES cos(p q / e)
p  n1/ 4
?
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Phase-slip Oscillator: Results
I. Semiclassical
Lorentzian
“Corkscrew”
NO non-linearities
UNUSUAL non-linearities
N= <n>
Number of photons
0
• Multiple solutions
• Enables experimental detection
Detuning
w
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Phase-slip Oscillator: Results
II. Quantum
1 semiclassical metastable state
?
1 SINGLE quantum state
Semiclassical
prediction
Quantum :
loops
n
• Confirms existence of meta-stable states
• Hysteresis
• Long life-times
Pure states
YES!
• Slow switching
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
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Phase-slip oscillator
Conclusions
• Novel system in superconducting electronics
• Unusual non-linearities
• At small number of photons
• Tunable with
• Usable in many applications
•ultrasensitive measurements, quantum manipulation, etc.
• Detection of quantum phase-slip
• Oscillatory dependence on gate voltage
• Measurement of responses of the oscillator
http://arxiv.org/abs/0912.3699
Quantum Engineering of States and Devices, 06.06.2010, Obergurgl
A.M. Hriscu, Phase-slip oscillator
(Submitted to PRL)
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