Fig. 6: Circuit for preparing the SU(3) thermal state of a unit cell with Nā=ā2.
From: The phase diagram of quantum chromodynamics in one dimension on a quantum computer
The circuit includes parameterised RX(Īø) rotations applied to the ancilla qubits, followed by a series of CNOT gates that entangle the ancilla qubits with the system qubits. Post-entanglement, a series of three four-body gates RYZZX(Ļ) with independent variational parameters is applied, followed by three two-body RZZ gates and a layer of parametrised RZ rotations. The unitary \({\hat{U}}_{S}({{{\boldsymbol{\varphi }}}})\) concludes with another series of three four-body gates. A measurement circuit \({\hat{M}}_{H}\), shown in the inset, is required for measuring the non-diagonal contribution \({\hat{H}}_{2}\) in the Hamiltonian. In total, 21 variational parameters are needed for the simulation.
