Quantum circuit construction with simultaneously entangling gates in trapped-ion quantum computers
A method of performing computation using an ion trap quantum computing system including a classical computer, a system controller, and a quantum processor includes computing, by the classical computer, a circuit that implements a selected set of gate operations, using one or more efficient arbitrary simultaneous entangling (EASE) gates, implementing, by the system controller, the computed circuit on the quantum processor, measuring, by the system controller, population of qubit states in the quantum processor, and outputting, by the classical computer, the measured population of qubit states in the quantum processor.
1. A method of performing computation using an ion trap quantum computing system comprising a classical computer, a system controller, and a quantum processor, comprising:
computing, by the classical computer, a circuit that implements a selected set of gate operations, using one or more efficient arbitrary simultaneous entangling (EASE) gates;
implementing, by the system controller, the computed circuit on the quantum processor;
measuring, by the system controller, population of qubit states in the quantum processor; and
outputting, by the classical computer, the measured population of qubit states in the quantum processor,
wherein the selected set of gate operations satisfies at least one of the following:
a) the selected set of gate operations comprises a layer of one or more controlled Z gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises a single EASE gate and single-qubit gates,
b) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 2n EASE gates and single-qubit gates,
c) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 6 log n EASE gates and single-qubit gates, using n/2 ancillary qubits,
d) the selected set of gate operations comprises a multi-controlled NOT gate acting on n qubits in the quantum processor, and the computed circuit comprises 3n/2 EASE gates and single-qubit gates,
e) the selected set of gate operations comprises a qubit permutation gate acting on n qubits in the quantum processor, and the computed circuit comprises 12 EASE gates and single-qubit gates using n ancillary qubits, or 18 EASE gates and single-qubit gates not using n ancillary qubits, or
f) the selected set of gate operations comprises a controlled permutation gate acting on n qubits in the quantum processor, and the computed circuit comprises 0(1) EASE gates and single-qubit gates.
2. An ion trap quantum computing system, comprising:
a quantum processor comprising n qubits, each qubit comprising a trapped ion having two hyperfine states;
one or more lasers configured to emit a laser beam, which is provided to trapped ions in the quantum processor;
a classical computer configured to perform operations comprising:
computing a circuit that implements a selected set of gate operations, using one or more efficient arbitrary simultaneous entangling (EASE) gates; and
a system controller configured to execute a control program to control the one or more lasers to perform operations on the quantum processor, the operations comprising:
implementing the computed circuit on the quantum processor; and
measuring population of qubit states in the quantum processor,
wherein the classical computer is further configured to output the measured population of qubit states in the quantum processor, and
the selected set of gate operations satisfies at least one of the following:
a) the selected set of gate operations comprises a layer of one or more controlled Z gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises a single EASE gate and single-qubit gates,
b) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 2n EASE gates and single-qubit gates,
c) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 6 log n EASE gates and single-qubit gates, using n/2 ancillary qubits,
d) the selected set of gate operations comprises a multi-controlled NOT gate acting on n qubits in the quantum processor, and the computed circuit comprises 3n/2 EASE gates and single-qubit gates,
e) the selected set of gate operations comprises a qubit permutation gate acting on n qubits in the quantum processor, and the computed circuit comprises 12 EASE gates and single-qubit gates using n ancillary qubits, or 18 EASE gates and single-qubit gates not using n ancillary qubits, or
f) the selected set of gate operations comprises a controlled permutation gate acting on n qubits in the quantum processor, and the computed circuit comprises 0(1) EASE gates and single-qubit gates.
3. An ion trap quantum computing system, comprising:
a classical computer;
a quantum processor comprising n qubits, each qubit comprising a trapped ion having two hyperfine states;
a system controller configured to execute a control program to control the one or more lasers to perform operations on the quantum processor; and
non-volatile memory having a number of instructions stored therein which, when executed by one or more processors, causes the ion trap quantum computing system to perform operations comprising:
computing, by the classical computer, a circuit that implements a selected set of gate operations, using one or more efficient arbitrary simultaneous entangling (EASE) gates;
implementing, by the system controller, the computed circuit on the quantum processor;
measuring, by the system controller, population of qubit states in the quantum processor; and
outputting, by the classical computer, the measured population of qubit states in the quantum processor,
wherein the selected set of gate operations satisfies at least one of the following:
a) the selected set of gate operations comprises a layer of one or more controlled Z gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises a single EASE gate and single-qubit gates,
b) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 2n EASE gates and single-qubit gates,
c) the selected set of gate operations comprises a layer of one or more controlled NOT gates, each of which is applied on a pair of qubits among n qubits in the quantum processor, and the computed circuit comprises 6 log n EASE gates and single-qubit gates, using n/2 ancillary qubits,
d) the selected set of gate operations comprises a multi-controlled NOT gate acting on n qubits in the quantum processor, and the computed circuit comprises 3n/2 EASE gates and single-qubit gates, or
e) the selected set of gate operations comprises a qubit permutation gate acting on n qubits in the quantum processor, and the computed circuit comprises 12 EASE gates and single-qubit gates using n ancillary qubits, or 18 EASE gates and single-qubit gates not using n ancillary qubits.