Quantum Algorithms

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Entanglement generated by Dissipation
Christine Muschik and J. Ignacio Cirac
Max-Planck-Institut für Quantenoptik
Hanna Krauter, Kasper Jensen, Jonas Meyer
Petersen and Eugene Polzik
Niels Bohr Institute, Danish Research Foundation
Center for Quantum Optics (QUANTOP)
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Entanglement
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Entanglement
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Steady State Entanglement
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Motivation
Quantum entanglement
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Motivation
Quantum entanglement
Typically
Quantum states are fragile under decoherence
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Motivation
Quantum entanglement
Typically
Quantum states are fragile under
decoherence Avoidance of dissipation by
decoupling the system from the environment
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Motivation
Quantum entanglement
Typically
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Motivation
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Motivation
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Motivation
New approaches
Use the interaction of the system with the
environment
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Motivation
New approaches
Use the interaction of the system with the
environment Dissipation drives the system into
the desired state
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Motivation
New approaches
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Motivation
Procedure
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Motivation
Procedure
Engineer the coupling
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Motivation
Procedure
Engineer the coupling Steady state desired
state
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Motivation
Procedure
Engineer the coupling Steady state desired
state Arbitrary initial state
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Motivation
Procedure
Engineer the coupling Steady state desired
state Arbitrary initial state
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Motivation
Procedure
Engineer the coupling Steady state desired
state Arbitrary initial state
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Motivation
Procedure
Engineer the coupling Steady state desired
state Arbitrary initial state
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Setup
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Main idea
Hamiltonian
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Main idea
Hamiltonian
Master equation
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Main idea
Hamiltonian
Master equation
Unique Steady State
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Setup
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Setup
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Setup
laser
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Setup
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Setup
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Setup
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Setup
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Theory
Masterequation
undesired processes
Entanglement
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Theory
Entanglement ideal case
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Theory
Entanglement ideal case
Entanglement including undesired processes
noise rate
polarization
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Experimental realization of purely dissipation
based entanglement
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Experimental realization of purely dissipation
based entanglement
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Experimental results
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Experimental results
EPR variance
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Experimental results
Longitudinal spin
EPR variance
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Experimental results
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Conclusions and Outlook
First observation of entanglement generated by
dissipation
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Conclusions and Outlook
First observation of entanglement generated by
dissipation
Entanglement was produced with macroscopic atomic
ensembles, and lasted much longer than in
previous experiments where entanglement was
generated using standard methods.
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Conclusions and Outlook
First observation of entanglement generated by
dissipation
Entanglement was produced with macroscopic atomic
ensembles, and lasted much longer than in
previous experiments where entanglement was
generated using standard methods.
This work paves the way towards the creation of
long lived entanglement, potentially lasting for
several minutes or longer.
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Conclusions and Outlook
Realization of Steady State Entanglement
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Conclusions and Outlook
Realization of Steady State Entanglement
Increased optical depth optical pumping
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Conclusions and Outlook
Realization of Steady State Entanglement
Increased optical depth optical pumping
Reduced spin-flip collisions
Better coatings, lower temperatures
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Summary
Proposal for long-lived entanglement
Dissipatively driven entanglement
General theoretical model for quadratic
Hamiltonians
Future
Other systems, e.g. optomechanical oscillators
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Main idea
Steady state
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Effective ground state Hamiltonian
Master equation
Entanglement