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.


(Color online) Different parameter values as a function of the external flux . Here , , ,  (dotted solid lines), and , , ,  (dashed lines). (a) The ratio  determines the region of external flux in which perturbation theory is still valid. (b) Behavior of  and , [ (dotted solid lines) and  (dashed lines)]. Tuning the external magnetic flux, the regimes (i) , , (ii) , and (iii) , , can be reached. (c) Tunability of the ratio . For the situation plotted with dashed lines, at  we find , and , giving rise to a ring-exchange interaction only. In the vicinity of that point, the ratio  can go from positive to negative values.
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f000035: (Color online) Different parameter values as a function of the external flux . Here , , , (dotted solid lines), and , , , (dashed lines). (a) The ratio determines the region of external flux in which perturbation theory is still valid. (b) Behavior of and , [ (dotted solid lines) and (dashed lines)]. Tuning the external magnetic flux, the regimes (i) , , (ii) , and (iii) , , can be reached. (c) Tunability of the ratio . For the situation plotted with dashed lines, at we find , and , giving rise to a ring-exchange interaction only. In the vicinity of that point, the ratio can go from positive to negative values.

Mentions: In Fig. 7 we show the behavior of the different system parameters as a function of the external flux. A fine-tuning of the ’s ensures that for the conditions (31) and (32) are fulfilled. Typical values of the coupling constants in the region of magnetic flux where the perturbative approach leading to Eq. (15) is still valid () are , , still much larger than the standard decoherence rates of a few tens of kHz. As we will show below, the tunability shown in Fig. 7 allows us to access the different phases of the model (15).


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)

(Color online) Different parameter values as a function of the external flux . Here , , ,  (dotted solid lines), and , , ,  (dashed lines). (a) The ratio  determines the region of external flux in which perturbation theory is still valid. (b) Behavior of  and , [ (dotted solid lines) and  (dashed lines)]. Tuning the external magnetic flux, the regimes (i) , , (ii) , and (iii) , , can be reached. (c) Tunability of the ratio . For the situation plotted with dashed lines, at  we find , and , giving rise to a ring-exchange interaction only. In the vicinity of that point, the ratio  can go from positive to negative values.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

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

f000035: (Color online) Different parameter values as a function of the external flux . Here , , , (dotted solid lines), and , , , (dashed lines). (a) The ratio determines the region of external flux in which perturbation theory is still valid. (b) Behavior of and , [ (dotted solid lines) and (dashed lines)]. Tuning the external magnetic flux, the regimes (i) , , (ii) , and (iii) , , can be reached. (c) Tunability of the ratio . For the situation plotted with dashed lines, at we find , and , giving rise to a ring-exchange interaction only. In the vicinity of that point, the ratio can go from positive to negative values.
Mentions: In Fig. 7 we show the behavior of the different system parameters as a function of the external flux. A fine-tuning of the ’s ensures that for the conditions (31) and (32) are fulfilled. Typical values of the coupling constants in the region of magnetic flux where the perturbative approach leading to Eq. (15) is still valid () are , , still much larger than the standard decoherence rates of a few tens of kHz. As we will show below, the tunability shown in Fig. 7 allows us to access the different phases of the model (15).

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.