Partially Symmetric Quantum-Logic Circuit Verification via Direct Sums

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Testing quantum-logic circuits with multiple states is resource-intensive due to the need to verify a large number of input combinations, unlike binary logic which only requires binary states of 0 and 1, leading to a geometric increase in required tests.

Innovation Solution

The method employs direct sums and invariance groups to identify permutations that do not change the output of partially symmetric quantum-logic circuits, allowing for the reduction of necessary tests by grouping inputs and generating a direct sum of permutation operations that preserve the circuit's functionality.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If comprehensive testing of all input combinations is performed on quantum-logic circuits, then testing completeness is improved, but resource consumption increases exponentially

Engineering Contradiction:
Improvetesting completenessVSAvoidresource consumption
Core Design Contradiction:
ReliabilityVSQuantity of substance

Solution Approach 1:

The patent segments the set of all possible input combinations into equivalence classes based on symmetry relationships. By dividing the testing space into these classes and selecting representative inputs from each class, the method achieves comprehensive coverage while reducing the total number of tests required. This segmentation transforms the exponential testing problem into a manageable set of representative tests.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent identifies symmetry groups that represent universal transformations preserving circuit functionality. These symmetry operations serve multiple purposes: they define equivalence classes for test reduction, characterize circuit properties, and generate test suites that are universally applicable to any circuit exhibiting the identified symmetries. The symmetry groups thus perform multiple functions in the testing process.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Adaptability or versatility

If the number of input states in quantum-logic circuits is increased, then circuit functionality is improved, but testing complexity increases geometrically

Engineering Contradiction:
Improvecircuit functionalityVSAvoidtesting complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent exploits the asymmetry between the large state space of quantum-logic circuits and the smaller symmetry group structure. By identifying and utilizing the asymmetric properties of symmetry operations, the method reduces testing complexity without sacrificing the ability to handle circuits with many input states. The symmetry analysis reveals structural patterns that simplify testing despite increased circuit functionality.

Inventive Principle:
Principle #4Asymmetry

Solution Approach 2:

The patent changes the parameter space from individual input combinations to symmetry group parameters. Instead of testing each of the exponentially many input states individually, the method tests based on symmetry orbit representatives and stabilizer properties. This parameter transformation reduces testing complexity from exponential to polynomial in the number of inputs and states.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentUS10082539B2Using direct sums and invariance groups to test partially symmetric quantum-logic circuits
Publication Date: 2018.09.25 KYNDRYL INC
  • US10082539B2 patent drawing
  • US10082539B2 patent drawing
  • US10082539B2 patent drawing

AI summary

A method and associated systems for using direct sums and invariance groups to optimize the testing of partially symmetric quantum-logic circuits is disclosed. A test system receives information that describes the architecture of a quantum-logic circuit to be tested. The system uses this information to organize the circuit's inputs into two or more mutually exclusive subsets of inputs. The system computes a direct sum of a set of groups associated with the subsets in order to generate an invariance group that contains one or more invariant permutations of the circuit's inputs. These invariant permutations can be used to reduce the number of tests required to fully verify the circuit for all possible input vectors. Once one specific input vector has been verified, there is no need to test other vectors that can be generated by performing any one of the invariant permutations upon the previously verified vector.