Quantum Annealing Hardware With a Dynamic Quantum Governor
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Quantum annealing processes face non-adiabaticity due to thermal fluctuations and excitations, leading to inaccurate results in solving hard combinatorial optimization problems, such as NP-hard problems and machine learning tasks, as the quantum processor may deviate from the ground state of the Hamiltonian.
Innovation Solution
Incorporating a quantum governor (QG) into the quantum hardware to navigate the quantum evolution robustly, suppressing excitations during the initial phase and enhancing thermal fluctuations for relaxation to the ground state, using a programmable quantum chip with logical and control qubits to manage environmental interactions and disorders.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If quantum annealing is performed without suppression mechanisms, then thermal fluctuations cause excitations to higher energy states, but the quantum processor can still reach the ground state through natural relaxation
Solution Approach 1:
The quantum governor applies a preliminary counteracting force against thermal excitations before they can significantly populate excited states. By introducing an energy penalty proportional to the excited state population during early annealing stages, the system preemptively suppresses harmful excitations, allowing more reliable ground state preparation without excessive energy loss.
Solution Approach 2:
The quantum governor implements a feedback mechanism where the Hamiltonian dynamically adjusts based on the instantaneous excited state population. The governor strength parameter scales with the annealing parameter, creating a feedback loop that automatically strengthens suppression when excitations occur and relaxes as the system approaches the ground state, thereby improving fidelity while minimizing energy loss.
2Reliability
If quantum governor strength is increased to suppress excitations, then ground state fidelity improves, but the system may freeze in suboptimal solutions
Solution Approach 1:
The quantum governor strength is made dynamic rather than static, scaling with the annealing parameter s(t). During early annealing when thermal excitations are most problematic, the governor strength is high to suppress excitations. As annealing progresses and the transverse field decreases, the governor strength naturally diminishes, allowing the system to relax to the ground state without being overly constrained, thus preventing freezing in suboptimal solutions.
Solution Approach 2:
The quantum governor operates in a periodic manner relative to the annealing schedule, being most active during critical early phases when excitations occur and gradually becoming less active as the system approaches completion. This periodic modulation of suppression strength ensures ground state fidelity is maximized during vulnerable periods while maintaining adaptability during later relaxation phases.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Improves the adiabatic quantum computation by increasing the fidelity of reaching the ground state, preventing premature freezing in suboptimal solutions, and enhancing the robustness of quantum annealing processes.
Implementation Method 1
The quantum hardware performs adiabatic quantum computation starting with a known ground state of a known initial Hamiltonian. Over time, as the known initial Hamiltonian evolves into the Hamiltonian for solving the problem, the known ground state evolves and remains at the instantaneous ground state of the evolving Hamiltonian.
Implementation Method 2
Sometimes the quantum adiabatic computation becomes non-adiabatic due to excitations caused, e.g., by thermal fluctuations.
Implementation Method 3
ensuring the system remains in the ground state by engineering dissipative dynamics and interacting with the environment to enhance thermal fluctuations
Implementation Method 4
the quantum hardware is also constructed and programmed to assist relaxation from higher energy states to lower energy states or the ground state during a later stage of the computation
Data Source
AI summary
Methods, systems, and apparatus, including computer programs encoded on computer storage media, for constructing and programming quantum hardware for quantum annealing processes.