Quantum annealing debugging systems and methods
Computational systems and methods employ characteristics of a quantum processor determined or sampled between a start and an end of an annealing evolution per an annealing schedule. The annealing evolution can be reinitialized, reversed or continued after determination. The annealing evolution can be interrupted. The annealing evolution can be ramped immediately prior to or as part of determining the characteristics. The annealing evolution can be paused or not paused immediately prior to ramping. A second representation of a problem can be generated based at least in part on the determined characteristics from an annealing evolution performed on a first representation of the problem. The determined characteristics can be autonomously compared to an expected behavior, and alerts optionally provided and/or the annealing evolution optionally terminated based on the comparison. Iterations of annealing evolutions may be performed until an exit condition occurs.
1. A method of operation of a control system communicatively coupled to a quantum processor, the control system comprising at least one processor and at least one nontransitory processor-readable medium that stores at least one of processor-executable instructions or data, the method comprising:
determining, by the control system, an annealing evolution schedule to perform a quantum annealing evolution computation on a problem representation in a quantum processor, the annealing evolution schedule comprising varying an annealing variable from an initial value, through an intermediary value, to a final value over a time interval, the time interval comprising a start of the annealing evolution schedule at the initial value of the annealing variable, a completion of the annealing evolution schedule at the final value of the annealing variable, and an intermediary time between the start of the annealing evolution schedule and before a completion of the annealing evolution schedule at the intermediary value of the annealing variable;
causing, by the control system, a start of at least a first iteration of the quantum annealing evolution computation on the problem representation in the quantum processor in accordance with the annealing evolution schedule; and
at least once during the time interval of the annealing evolution schedule:
determining, by the control system, at least one characteristic of the quantum processor at the intermediary time;
comparing the at least one determined characteristic to at least one corresponding predetermined expected characteristic;
in response to the at least one determined characteristic diverging from the at least one corresponding predetermined expected characteristic by a defined threshold, recasting the problem representation; and
using the recast problem representation, causing, by the control system, at least one of: a reinitializing of the annealing evolution schedule, a reversal of the annealing evolution schedule from the intermediary time at which the at least characteristic was determined toward the start of the annealing evolution schedule, or a continuing of the annealing evolution schedule from the intermediary time at which the at least characteristic was determined.
2. The method of claim 1 , further comprising:
causing, by the control system, at least one interruption of the quantum annealing evolution computation of the quantum processor before completion of the annealing evolution schedule.
3. The method of claim 2 wherein the determining at least one characteristic of the quantum processor occurs during the at least one interruption of the quantum annealing evolution computation before completion of the annealing evolution schedule.
4. The method of claim 1 , further comprising:
causing, by the control system, a ramping of the annealing variable on at least a portion of the quantum processor before completion of the annealing evolution schedule, wherein the determining at least one characteristic of the quantum processor occurs concurrently with or immediately following the ramping.
5. The method of claim 4 , further comprising:
causing, by the control system, a pausing of the annealing evolution schedule immediately prior to the ramping.
6. The method of claim 4 wherein the causing of the ramping of the annealing variable on at least the portion of the quantum processor occurs without causing a pausing of the annealing evolution schedule immediately prior to the ramping.
7. The method of claim 1 wherein determining at least one characteristic comprises reading out a state of each of a number of qubits.
8. The method of claim 1 wherein determining at least one characteristic comprises reading out a state of each of a number of qubits via a number of weakly coupled detectors.
9. The method of claim 1 wherein determining at least one characteristic comprises continually reading out a state of each of a number of qubits via a number of weakly coupled detectors during the quantum annealing evolution computation.
10. The method of claim 1 , further comprising:
autonomously comparing, by the control system, the at least one determined characteristic of the quantum processor to a set of user specified dynamics.
11. The method of claim 1 , further comprising:
autonomously identifying, by the control system, a deviation from a set of user specified dynamics; and
producing an alert, by the control system, in response to identification of a deviation from the set of user specified dynamics that exceeds a threshold deviation.
12. The method of claim 1 , further comprising:
autonomously identifying, by the control system, an occurrence of an event based at least in part on the at least one determined characteristic of the quantum processor; and
producing an alert, by the control system, in response to identification of the event.
13. The method of any of claim 10 , further comprising:
receiving, by the control system, a user specified expected behavior expected to occur during at least one iteration of the quantum annealing evolution computation, the user specified expected behavior specified as at least one mathematical model.
14. The method of claim 1 , further comprising:
providing to an end user device, via the control system, a representation of a behavior during a portion of the annealing evolution schedule, subsequent to performance of the portion of the annealing evolution schedule on the quantum processor.
15. The method of claim 14 , further comprising:
transforming, via the control system, a set of low level machine state information into a set of higher level representation information.
16. The method of claim 1 , further comprising:
repeatedly:
determining, by the control system, at least one characteristic of the quantum processor at a series of subsequent times between the intermediary time in the annealing evolution schedule and the completion of the annealing evolution schedule; and
causing, by the control system, at least one of: a reinitializing of the annealing evolution schedule, a reversal of the annealing evolution schedule from a selected subsequent time at which the at least characteristic was determined, or a continuing of the annealing evolution schedule from a selected subsequent time at which the at least characteristic was determined.
17. A system, comprising:
a quantum processor;
a control system communicatively coupled to the quantum processor, the control system comprising at least one processor and at least one nontransitory processor-readable medium that stores at least one of processor-executable instructions or data which, when executed by the at least one processor, causes the at least one processor to:
determine an annealing evolution schedule to perform a quantum annealing evolution computation on a problem representation in a quantum processor, the annealing evolution schedule comprising varying an annealing variable from an initial value, through an intermediary value, to a final value over a time interval, the time interval comprising a start of the annealing evolution schedule at the initial value of the annealing variable, a completion of the annealing evolution schedule at the final value of the annealing variable, and an intermediary time between the start of the annealing evolution schedule and before a completion of the annealing evolution schedule at the intermediary value of the annealing variable;
start at least a first iteration of the quantum annealing evolution computation on the problem representation in the quantum processor in accordance with the annealing evolution schedule; and
at least once during the time interval of the annealing evolution schedule,
determine at least one characteristic of the quantum processor at the intermediary time;
compare the at least one determined characteristic to at least one corresponding predetermined expected characteristic;
where the at least one determined characteristic diverges from the at least one corresponding predetermined expected characteristic by a defined threshold, recast the problem representation; and
using the recast problem representation, cause at least one of: a reinitialization of the annealing evolution schedule, a reversal of the annealing evolution schedule from the intermediary time at which the at least one characteristic was determined toward the start of the annealing evolution schedule, or a continuation of the annealing evolution schedule from the intermediary time at which the at least characteristic was determined.
18. The system of claim 17 wherein the processor-executable instructions or data, when executed, cause the at least one processor to: cause at least one interruption of the quantum annealing evolution computation of the quantum processor before completion of the annealing evolution schedule, and determine the at least one characteristic of the quantum processor during the interruption.
19. The system of claim 17 wherein the processor-executable instructions or data, when executed, cause the at least one processor to: ramp the annealing variable on at least a portion of the quantum processor before completion of the annealing evolution schedule, and determine the at least one characteristic of the quantum processor at the intermediary time concurrently with or immediately following the ramping.
20. The system of claim 19 wherein the processor-executable instructions or data, when executed, cause the at least one processor to: pause the annealing evolution schedule immediately prior to the ramping.