Transcript Kvantu fizika bez mistikas

Slava Kashcheyevs (Uni Latvia)
Thermo 2013, RWTH Aachen, November 25, 2013
VK and J.Timoshenko, Phys. Rev. Lett. 109, 216801(2012)
L. Fricke et al, Phys. Rev. Lett. 110, 126803 (2013)
S. S Fahlvik Svensson et al, New J Phys 15, 105011 (2013)


“
” = gradual decoupling of a
finite system from macroscopic environment
An important part of protocol for:
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◦
◦
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on-demand few-particle sources
microscopic heat engines/pumps
selective quantum state preparation
…
Quantum
coherence
Nonequillibrium
Coulomb
interactions

Single spinless level coupled to a Fermi lead
equilibrium
(coupling=const)
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
Exactly solvable for any
Phase memory can be neglected if:
- timescale
of decoupling,
e.g.
non-Markovian
effects if violated!
Jauho,Meir,
Wingreen’94
Flensberg,
Pustilnik,
Niu’1999
VK,
Timoshenko,
’2013
“Plunger-to-barrier” ratio
(crosscoupling strength)
Δptb breaks particlehole symmetry!
adaiabtic
Non-perturbative, non-Markovian
asymptotics dominates the tail!
decoupled
I/(ef)
Moving the decoupling
point determines the
captured charge (=moves
)
LOAD
V1
Decouple
1
capture 0
0
capture 1
1
Couple
UNLOAD
V2



0
capture
isolate
eject
V2
Data: L.Fricke, Uni.Hannover
Quantum
coherence
Nonequillibrium
Quantum
coherence
Nonequillibrium
Coulomb
interactions
Need both excitation and backtunneling:
Balancing the interferometer!


Non-adiabatic excitation
(Landau-Zener)
Adiabatic
“elevator”
Quantum
coherence
Nonequillibrium
Coulomb
interactions
Quantum
coherence
Nonequillibrium
Coulomb
interactions
Quantum
coherence
Nonequillibrium
Coulomb
interactions
-?

Adiabatic side of the disequlibration crossover:
Load
Hold
Detect!

Rate equations for the slow degree of freedom:
detailed balance:

Fermi function

Transitions n-1↔n “freeze” sequentially as
See M. Esposito’s talk!
Adiabatic constant
Non-adiabatic decay
follows equilibium
Backtunneling onset

Final capture probability:
VK and B.Kaestner, Phys. Rev. Lett. 104, 186805 (2010)
Simple fitting formulas if
backtunneling dominates
Data: PTB group;
Hohls et al, PRL’2012
Rescaled gate voltage
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Generalized grand
canonical (thermal)

Generalized decay
cascade (athermal)
Phenomenological
parametric ansatz
L. Fricke et al, Phys. Rev. Lett. 110, 126803 (2013)
Quantum
coherence
Nonequillibrium



Coulomb
interactions
Equlibrium Anderson model is rich & well-studied
RG for gradual quenches?
Dynamical scaling near “quantum critical” point?
VK, Karrasch, Hecht,
Weichselbaum, Meden,
Schiller PRL’09

Spin and orbital intradot excitations:
◦ Spin-charge separation in mixed-valence/Kondo transition
◦
See talk by Heiner Linke!
Thank you!
S. S Fahlvik Svensson et al, New J Phys 15, 105011 (2013)