Gatesets

To synthesize with different gates or topologies, you will need to create an instance of an search_compiler.gatesets.Gateset subclass.

# example: synthesizing for the ring topology
import search_compiler as sc
ring_gateset = sc.gatesets.QubitCNOTRing()

# use your gateset with a project
myproject = sc.Project("myproject")
myproject["gateset"] = ring_gateset

# or use it with SearchCompiler directly
mycompiler = sc.SearchCompiler(gateset=ring_gateset)

Provided Gatesets

Basic Gatesets

• QubitCNOTLinear - a gateset that is useful for synthesizing circuits with CNOTs and single qubit gates with the linear topology. It is similar to QiskitU3Linear, but is slightly more efficient without sacrificing generality. It is the default gateset.
• QiskitU3Linear - a gateset based on IBM's U3 gate and CNOTs for the linear topology. It is generally better to use QubitCNOTLinear, which is more efficient.
• ZXZXZCNOTLinear - a gateset based on the RZ-RX90-RZ-RX90-RZ decomposition of single qubit gates for the linear topology. It is generally better to use QiskitU3Linear, which is more efficient.

Nonlinear Topologies

• QubitCNOTRing - a gateset that is equivalent to QubitCNOTLinear except it implements the ring topology. For 3 qubits, this is the triangle topology and is all-to-all.
• QubitCNOTAdjacencyList - a gateset that takes a list of CNOT connections, and creates a gateset that is similar to QubitCNOTLinear but uses a toplogy based on the adjacency list. If the desired topology can be achieved by using QubitCNOTLinear or QubitCNOTRing, it is recommended to choose one of those because it will be more efficient.

# This would create a gateset for 4 qubits with CNOT connections 0 to 1, 0 to 2, and 1 to 3
mygateset = sc.gatesets.QubitCNOTAdjacencyList([(0,1), (0,2), (1,3)])

Nonstandard Gates

• QubitCRZLinear - a gateset that explores the usage of two sqrt(CNOT) gates and a Z gate to form a CRZ gate instead of a normal CNOT gate.
• QubitCRZRing - a gateset that is similar to QubitCRZLinear but implements the ring topology. For 3 qubits, the ring toplogy is the triangle topology and is fully connected.

Qutrits

• QutritCPIPhaseLinear - a gateset designed for qutrits that uses single qutrit gates and the CPI two-qutrit gate with a phase applied.

Custom Gatesets

If none of these gatesets suite your needs, you can write your own! Make a subclass of sc.gatesets.Gateset and implement these two functions:

• intial_layer(dits) The single input, dits, is an integer which describes how many qudits will be in the circuit. The function returns a single sc.circuits.QuantumStep object representing an initial layer for the search. Normally, this is a kronecker product of single-qudit gates, and you can use the provided fill_row helper function to produce this.
• search_layers(dits) The single input, dits, is an integer which describes how many qudits will be in the circuit. The function returns a list of sc.circuits.QuantumStep objects, each representing a possible building block in a possible location for expanding the current circuit.

See the existing implementations in sc.gatesets for examples of how to write a gateset.