Commit aee98319 authored by Nguyen, Thien Minh's avatar Nguyen, Thien Minh
Browse files

Simplify Q# benchmark source 



Direct trotter evolve, no wrapping in standard lib.

Signed-off-by: default avatarThien Nguyen <nguyentm@ornl.gov>
parent 79b080e0

benchmarks/openqasm3/trotter/qsharp/trotter.qs

+9 −43
Original line number Diff line number Diff line
@@ -9,47 +9,7 @@ namespace Benchmark.Heisenberg { 
    // an Heisenberg model: 

    //     H ≔ - J Σ'ᵢⱼ Zᵢ Zⱼ - hX Σᵢ Xᵢ

    // where the primed summation Σ' is taken only over nearest-neighbors.



    operation _Heisenberg1DTrotterUnitaries(nSites : Int, hXCoupling : Double, jCoupling : Double, idxHamiltonian : Int, stepSize : Double, qubits : Qubit[])

    : Unit

    is Adj + Ctl {

        // when idxHamiltonian is in [0, nSites - 1], apply transverse field "hx"

        // when idxHamiltonian is in [nSites, 2 * nSites - 1], apply Heisenberg coupling "jC"

        if (idxHamiltonian <= nSites - 1) {

            Exp([PauliX], (-1.0 * hXCoupling) * stepSize, [qubits[idxHamiltonian]]);

        } 

        else {

            Exp([PauliZ, PauliZ], (-1.0 * jCoupling) * stepSize, qubits[idxHamiltonian % nSites .. (idxHamiltonian + 1) % nSites]);

        }

    }



    // The input to the Trotterization control structure has a type

    // (Int, ((Int, Double, Qubit[]) => () is Adj + Ctl))

    // The first parameter Int is the number of terms in the Hamiltonian

    // The first parameter in ((Int, Double, Qubit[])) is an index to a term

    // in the Hamiltonian

    // The second parameter in ((Int, Double, Qubit[])) is the stepsize

    // The third parameter in  ((Int, Double, Qubit[])) are the qubits the

    // Hamiltonian acts on.

    // Let us create this type from Heisenberg1DTrotterUnitariesImpl by partial

    // applications.

    function Heisenberg1DTrotterUnitaries(nSites : Int, hXCoupling : Double, jCoupling : Double)

    : (Int, ((Int, Double, Qubit[]) => Unit is Adj + Ctl)) {

        let nTerms = 2 * nSites - 1;

        return (nTerms, _Heisenberg1DTrotterUnitaries(nSites, hXCoupling, jCoupling, _, _, _));

    }



    // We now invoke the Trotterization control structure. This requires two

    // additional parameters -- the trotterOrder, which determines the order

    // the Trotter decompositions, and the trotterStepSize, which determines

    // the duration of time-evolution of a single Trotter step.

    function Heisenberg1DTrotterEvolution(nSites : Int, hXCoupling : Double, jCoupling : Double, trotterOrder : Int, trotterStepSize : Double)

    : (Qubit[] => Unit is Adj + Ctl) {

        let op = Heisenberg1DTrotterUnitaries(nSites, hXCoupling, jCoupling);

        return DecomposedIntoTimeStepsCA(op, trotterOrder)(trotterStepSize, _);

    }



    operation HeisenbergTrotterEvolve(nSites : Int, simulationTime : Double, trotterOrder : Int, trotterStepSize : Double) : Unit {

    operation HeisenbergTrotterEvolve(nSites : Int, simulationTime : Double, trotterStepSize : Double) : Unit {

        // We pick arbitrary values for the X and J couplings

        let hXCoupling = 1.0;

        let jCoupling = 1.0;
@@ -66,7 +26,13 @@ namespace Benchmark.Heisenberg { 
        use qubits = Qubit[nSites];

        // We then evolve for some time

        for idxStep in 0 .. steps - 1 {

            Heisenberg1DTrotterEvolution(nSites, hXCoupling, jCoupling, trotterOrder, trotterStepSizeResized)(qubits);

            for i in 0 .. nSites - 1 {

                Exp([PauliX], (-1.0 * hXCoupling) * trotterStepSizeResized, [qubits[i]]);

            }

            for i in 0 .. nSites - 2 {

                Exp([PauliZ, PauliZ], (-1.0 * jCoupling) * trotterStepSizeResized, qubits[i .. (i + 1)]);

            }

            

        }

    }
@@ -74,6 +40,6 @@ namespace Benchmark.Heisenberg { 
    // to be equivalent to OpenQASM3

    @EntryPoint()

    operation CircuitGen() : Unit {

        HeisenbergTrotterEvolve(5, 1.0, 1, 0.01);

        HeisenbergTrotterEvolve(50, 1.0, 0.01);

    }

}
 
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