sqrt overloads sqrt
y = sqrt(x)
The operator is implemented using a graph representation based on a second-order cone programming model, and can thus only be used in scenarios where YALMIP can propagate convexity. If you want to avoid a graph-representation using second-order cone constraints and instead use a standard nonlinear programming approach, use sqrtm instead.
Read more about the difference between sqrt and sqrtm in YALMIP