Limits...
Two-dimensional lattice gauge theories with superconducting quantum circuits.

Marcos D, Widmer P, Rico E, Hafezi M, Rabl P, Wiese UJ, Zoller P - Ann Phys (N Y) (2014)

Bottom Line: Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well.We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories.The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

View Article: PubMed Central - PubMed

Affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.

ABSTRACT

A quantum simulator of [Formula: see text] lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

No MeSH data available.


Ground-state flux distribution in a lattice of five plaquettes. For  (a) the electric flux propagates from charge to anticharge through the center of the lattice, while for  (b) it propagates along the edges.
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f000065: Ground-state flux distribution in a lattice of five plaquettes. For (a) the electric flux propagates from charge to anticharge through the center of the lattice, while for (b) it propagates along the edges.

Mentions: As we have mentioned above, experimentally observing the dynamics of strings would give access to open questions about confinement in lattice gauge theories. In particular, performing time-resolved measurements would show the fluctuations of an initially-prepared string, and the formation of strands, a problem that, even for relatively small lattices, is challenging to simulate classically. In Fig. 13 we show two particular examples of the ground-state distribution of flux, for a lattice of five plaquettes. Here we have created a charge–anticharge pair at the edges (achieved by a violation of the Gauss law by initially exciting/de-exciting the corresponding qubits). For [Fig. 13(a)] the electric flux propagates from charge to anticharge mainly through the center of the lattice, while for [Fig. 13(b)] it propagates along the edges of the system. This effect corresponds to a flux fractionalization into different strands, as it was observed in  [47,49]. Experimentally, it would be interesting to investigate the time-dependence of this process, as well as the behavior as the ratio is varied.


Two-dimensional lattice gauge theories with superconducting quantum circuits.

Marcos D, Widmer P, Rico E, Hafezi M, Rabl P, Wiese UJ, Zoller P - Ann Phys (N Y) (2014)

Ground-state flux distribution in a lattice of five plaquettes. For  (a) the electric flux propagates from charge to anticharge through the center of the lattice, while for  (b) it propagates along the edges.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263216&req=5

f000065: Ground-state flux distribution in a lattice of five plaquettes. For (a) the electric flux propagates from charge to anticharge through the center of the lattice, while for (b) it propagates along the edges.
Mentions: As we have mentioned above, experimentally observing the dynamics of strings would give access to open questions about confinement in lattice gauge theories. In particular, performing time-resolved measurements would show the fluctuations of an initially-prepared string, and the formation of strands, a problem that, even for relatively small lattices, is challenging to simulate classically. In Fig. 13 we show two particular examples of the ground-state distribution of flux, for a lattice of five plaquettes. Here we have created a charge–anticharge pair at the edges (achieved by a violation of the Gauss law by initially exciting/de-exciting the corresponding qubits). For [Fig. 13(a)] the electric flux propagates from charge to anticharge mainly through the center of the lattice, while for [Fig. 13(b)] it propagates along the edges of the system. This effect corresponds to a flux fractionalization into different strands, as it was observed in  [47,49]. Experimentally, it would be interesting to investigate the time-dependence of this process, as well as the behavior as the ratio is varied.

Bottom Line: Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well.We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories.The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

View Article: PubMed Central - PubMed

Affiliation: Institute for Quantum Optics and Quantum Information of the Austrian Academy of Sciences, A-6020 Innsbruck, Austria.

ABSTRACT

A quantum simulator of [Formula: see text] lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

No MeSH data available.