const gamma = Math.PI / 2;
const beta  = Math.PI / 8;
const c = circuit(2);
// Uniform superposition
c.h(0); c.h(1);
// Cost unitary: implements exp(i * gamma * Z0Z1 / 2) up to global phase
c.cx(0, 1);
c.rz(-gamma, 1);
c.cx(0, 1);
// Mixer unitary: exp(-i * beta * (X0 + X1)) = Rx(2*beta) tensor Rx(2*beta)
c.rx(2 * beta, 0);
c.rx(2 * beta, 1);
return c;