Adiabatic Quantum Computing Qubit Coherence
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current quantum computing methods, particularly in the circuit model, face challenges in maintaining qubit coherence for extended periods, which is essential for practical implementation, and existing systems are limited in solving computational problems beyond the capabilities of classical computers.
Innovation Solution
The implementation of adiabatic quantum computing using a system of superconducting qubits that undergoes a gradual transition from an initialization Hamiltonian to a problem Hamiltonian, allowing quantum tunneling for a sufficient period to solve computational problems, and the use of impedance readout devices to determine the quantum state of the qubits.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the circuit model of quantum computation is used, then quantum gates can be applied to qubits to perform computations, but qubits cannot maintain coherence long enough to complete quantum error correction operations
Solution Approach 1:
The patent changes the fundamental parameter of quantum computation from discrete gate operations to continuous adiabatic evolution. By formulating computation as a continuous process where the Hamiltonian evolves from an initial form to a final form over time, the system can maintain coherence throughout the entire computation process without requiring separate coherence maintenance intervals for error correction.
Solution Approach 2:
The adiabatic quantum computation model ensures continuous evolution of the quantum system from the initial Hamiltonian to the final Hamiltonian. This continuous process eliminates the discontinuous nature of gate-based operations, allowing the quantum system to maintain coherence throughout the entire computation without interruption for error correction operations.
2Reliability
If quantum error correction is performed in the circuit model, then computational accuracy can be maintained, but the coherence time requirement becomes excessively long (1,000 times the single-gate time)
Solution Approach 1:
The patent fundamentally changes how quantum computation is performed by transitioning from discrete gate operations to continuous adiabatic evolution. This parameter change allows the system to maintain coherence throughout the entire computation process, eliminating the need for separate coherence maintenance intervals that would require 1,000 times the single-gate time.
Solution Approach 2:
The patent replaces the mechanical gate-based quantum error correction system with a continuous adiabatic evolution approach. Instead of performing discrete error correction operations that require extended coherence, the system uses continuous Hamiltonian evolution to naturally maintain quantum states and perform computations simultaneously.
3Duration of action of stationary object
If adiabatic quantum computation is used, then qubit coherence can be maintained during computation, but the system requires precise control of Hamiltonian transitions
Solution Approach 1:
The patent employs preliminary action by defining the initial Hamiltonian and final Hamiltonian before the computation begins. The adiabatic evolution path is pre-planned, allowing the system to automatically maintain coherence throughout the process without requiring real-time complex control adjustments during the actual computation.
Solution Approach 2:
The patent manages the complexity of Hamiltonian control by using a systematic parameter change approach. The Hamiltonian evolves continuously from an initial form to a final form through a well-defined interpolation process, transforming the complex control problem into a manageable parameter evolution problem that maintains coherence while reducing control complexity.
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
This approach enables the solution of computational problems that are hard for classical computers by maintaining qubit coherence and efficiently transitioning between states, thereby solving problems like MAXCUT and other optimization and simulation challenges.
Implementation Method 1
the plurality of qubits is set to an intermediate state in which quantum tunneling between individual basis states within each qubit in the plurality of qubits can occur
Implementation Method 2
the quantum system is adiabatically changed until it is described by the ground state of the problem Hamiltonian HP
Implementation Method 3
the state of the quantum system is then read out by probing an observable of the σX Pauli matrix operator
Data Source
AI summary
A method for quantum computing using a quantum system comprising a plurality of qubits is provided. The system can be in any one of at least two configurations at any given time including one characterized by an initialization Hamiltonian HO and one characterized by a problem Hamiltonian HP. The problem Hamiltonian HP has a final state. Each respective first qubit in the qubits is arranged with respect to a respective second qubit in the qubits such that they define a predetermined coupling strength. The predetermined coupling strengths between the qubits in the plurality of qubits collectively define a computational problem to be solved. In the method, the system is initialized to HO and is then adiabatically changed until the system is described by the final state of the problem Hamiltonian HP. Then the state of the system is read out by probing an observable of the σX Pauli matrix operator.