We provide necessary and sufficient conditions for the uniqueness of minimisers of the Ginzburg-Landau functional for $\mathbb{ R}^n$-valued maps under a suitable convexity assumption on the potential and for $H^{ 1/2} \cap L^\infty$ boundary data that is non-negative in a fixed direction $e\in \mathbb{ S}^{ n-1}$. Furthermore, we show that, when minimisers are not unique, the set of minimisers is generated from any of its elements using appropriate orthogonal transformations of $\mathbb{ R}^n$. We also prove corresponding results for harmonic maps
Categories: math.AP math-ph math.MP