Calculus of Variations and Geometric Measure Theory

D. Mazzoleni - C. Muratov - B. Ruffini

An optimal design problem for a charge qubit

created by mazzoleni on 17 May 2024
modified by ruffini on 23 May 2025

[BibTeX]

Accepted Paper

Inserted: 17 may 2024
Last Updated: 23 may 2025

Journal: Comm. in PDEs
Year: 2024

Abstract:

In this paper we introduce a simple variational model describing the ground state of a superconducting charge qubit. The model gives rise to a shape optimization problem that aims at maximizing the number of qubit states at a given gating voltage. We show that for small values of the charge optimal shapes exist and are $C^{2,\alpha}$-nearly spherical sets. In contrast, we prove that balls are not minimizers for large values of the charge and conjecture that optimal shapes do not exist, with the energy favoring disjoint collections of sets.


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