Energy relaxation spectroscopy using autler-townes effect
One or more systems, devices, computer program products and/or computer-implemented methods of use provided herein relate to analysis of qubit coherence parameters of a physical qubit layout of a quantum computer. A system can comprise a pulse component for transmitting signals to a qubit, a readout component for receiving signals form the qubit, a memory that stores computer executable component, and a processor that executes the computer executable components stored in the memory. The computer executable components are executable to cause the pulse component to generate a first pulse to drive the qubit, cause the pulse component to generate a second pulse comprising an Autler-Townes off-resonant tone, and determine a probability relative to the qubit, in view of a shift of the qubit to a shifted frequency caused by the second pulse.
1. A system, comprising:
a pulse component for transmitting signals to a qubit;
a readout component for receiving signals from the qubit;
a memory that stores computer executable components; and
a processor that executes the computer executable components stored in the memory, wherein the computer executable components are executable to:
cause the pulse component to generate a first pulse to drive the qubit;
cause the pulse component to generate a second pulse comprising an Autler-Townes off-resonant tone; and
determine a probability relative to the qubit, in view of a shift of the qubit to a shifted frequency caused by the second pulse.
2. The system of claim 1 , wherein the pulse component further ceases emission of the second pulse prior to emission of a third pulse, which third pulse facilitates readout of a state of the qubit by the readout component.
3. The system of claim 1 , wherein the pulse component further emits another pulse, after emission of the second pulse, further driving the qubit, and wherein the pulse component emits the second pulse having fixed drive amplitude and fixed tone frequency over one or more instances of a range of time for facilitating measurement by the readout component of qubit frequency shift.
4. The system of claim 1 , wherein the pulse component emits the second pulse having a varied drive amplitude and fixed tone frequency for a fixed time, or fixed drive amplitude and varied tone frequency for a fixed time, for facilitating measurement of a probability of energy relaxation of the qubit at one or more different frequencies shifted from the qubit frequency.
5. The system of claim 4 , wherein the computer executable components comprise:
a measurement component that determines the probability of a qubit measurement, of the qubit, resulting in a particular state at a fixed delay time and varying drive amplitude of the second pulse as a function of frequency shift.
6. The system of claim 1 , wherein the probability is determined at various time ranges absent measurement of plural relaxation times of the qubit at the plural time ranges.
7. The system of claim 1 , wherein the probability is of the qubit being found in another excited state, other than the excited state to which the qubit was initially driven to prior to application of the second pulse, after a specified time after cessation of the second pulse.
8. The system of claim 1 , wherein the probability at a shifted frequency is obtained absent application of magnetic flux bias, DC electric field, or mechanical strain to the qubit.
9. The system of claim 1 , wherein the first one or more pulses drive the qubit to an excited state of order 1 or higher.
10. A computer-implemented method, comprising:
emitting, by a system operatively coupled to a processor, one or more first pulses driving a qubit;
emitting, by the system, a second pulse comprising an Autler-Townes off-resonant tone and shifting the frequency of the qubit; and
determining, by the system, a probability relative to the qubit in view of the shift of the qubit to a shifted frequency caused by the second pulse.
11. The computer-implemented method of claim 10 , further comprising:
ceasing, by the system, emission of the second pulse prior to emission of a third pulse, which third pulse facilitates readout of a state of the qubit by the readout component absent application of magnetic flux bias, DC electric field, or mechanical strain to the qubit prior to the emission of the third pulse.
12. The computer-implemented method of claim 10 , further comprising:
emitting, by the system, another pulse, after emission of the second pulse, further driving the qubit; and
wherein the emitting, by the system, of the second pulse comprises emitting the second pulse having fixed drive amplitude and fixed tone frequency over one or more instances of a range of time for facilitating measurement by the readout component of qubit frequency shift.
13. The computer-implemented method of claim 10 ,
wherein the emitting, by the system, of the second pulse comprises emitting the second pulse having a varied drive amplitude and fixed tone frequency for a fixed time, or fixed drive amplitude and varied tone frequency for a fixed time, for facilitating measurement of a probability of energy relaxation of the qubit at one or more different frequencies shifted from the qubit frequency.
14. The computer-implemented method of claim 10 , further comprising:
determining, by the system, the probability of a qubit measurement, of the qubit, resulting in a particular state at a fixed delay time and varying drive amplitude of the second pulse as a function of frequency shift, wherein the probability is determined at one or more time ranges absent measurement of plural relaxation times of the qubit at the plural time ranges.
15. The computer-implemented method of claim 10 , wherein the probability is of the qubit being found in another excited state, other than the excited state to which the qubit was initially driven prior to application of the second pulse, after a specified time after cessation of the second pulse.
16. A computer program product facilitating a process to determine a probability relative to a qubit having been excited, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to:
cause emission, by the processor, of one or more first pulses driving a qubit;
cause emission, by the processor, of a second pulse comprising an Autler-Townes off-resonant tone and shifting the frequency of the qubit; and
determine, by the processor, a probability relative to the qubit in view of the shift of the qubit to a shifted frequency caused by the second pulse.
17. The computer program product of claim 16 , wherein the program instructions are further executable by the processor to cause the processor to:
cause emission, by the processor, of another first pulse, after emission of the second pulse, further driving the qubit; and
cause the emission, by the processor, of the second pulse having fixed drive amplitude and fixed tone frequency over one or more instances of a range of time for facilitating measurement by the readout component of qubit frequency shift.
18. The computer program product of claim 16 , wherein the program instructions are further executable by the processor to cause the processor to:
cause the emission, by the processor, of the second pulse having a varied drive amplitude and fixed tone frequency for a fixed time, or fixed drive amplitude and varied tone frequency for a fixed time, for facilitating measurement of a probability of energy relaxation of the qubit at one or more different frequencies shifted from the qubit frequency.
19. The computer program product of claim 16 , wherein the program instructions are further executable by the processor to cause the processor to:
determine, by the processor, the probability of a qubit measurement of the qubit resulting in a particular state at a fixed delay time and varying drive amplitude of the second pulse as a function of frequency shift, wherein the probability is determined at one or more time ranges absent measurement of plural relaxation times of the qubit at the plural time ranges.
20. The computer program product of claim 16 , wherein the probability is of the qubit being found in another excited state, other than the excited state to which the qubit was initially driven prior to application of the second pulse, after a specified time after cessation of the second pulse.