KR-102963731-B1 - Techniques for quantum error correction using boson modes and related systems and methods

KR102963731B1KR 102963731 B1KR102963731 B1KR 102963731B1KR-102963731-B1

Abstract

Some embodiments relate to a method for operating a circuit quantum electrodynamic system comprising physical qubits distributedly connected to a quantum mechanical oscillator, the method comprising the steps of measuring the parity of a first state of the quantum mechanical oscillator, and subsequently, measuring the parity of a second state of the quantum mechanical oscillator that is different from the first state, applying a first driving waveform to the quantum mechanical oscillator, and applying a second driving waveform to the physical qubits simultaneously with the application of the first driving waveform, wherein the first driving waveform and the second driving waveform are selected at least partially based on the result of comparing the measured parity of the second state with the measured parity of the first state.

Inventors

거빈 스티븐 엠.
지앙 리앙
마이클 마리오스 에이치.
실베리 마티
브라이어리 리차드 티.
알버트 빅터 브이.
살미레토 유하

Assignees

예일 유니버시티

Dates

Publication Date: 20260513
Application Date: 20161202
Priority Date: 20151204

Claims (20)

A method for operating a circuit quantum electrodynamic system comprising physical qubits distributedly connected to a quantum mechanical oscillator, A step of measuring the parity of the first state of the above quantum mechanical oscillator; Subsequently to the step of measuring the parity of the first state, a step of measuring the parity of a second state of the quantum mechanical oscillator, wherein the second state is different from the first state; A step of applying a first driving waveform to the quantum mechanical oscillator; and The method includes the step of applying a second driving waveform to the physical qubit simultaneously with the application of the first driving waveform, wherein The first driving waveform and the second driving waveform are selected at least partially based on the result of comparing the measured parity of the second state with the measured parity of the first state, and A method of operating a circuit quantum electrodynamic system in which the application of the first driving waveform and the second driving waveform at least partially transitions the quantum mechanical oscillator from the second state back to the first state.
A method for operating a circuit quantum electrodynamic system according to claim 1, wherein the first state and the second state are superpositions of the same plurality of photon number states, and the first state and the second state have different amplitudes.
A method for operating a circuit quantum electrodynamic system, wherein, in paragraph 2, the first driving waveform and the second driving waveform are configured based on the duration between the step of measuring the parity of the first state and the step of measuring the parity of the second state.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the step of measuring the parity of each of the first state and the second state includes the step of measuring the photon number parity in binary.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the first state is a superposition of multiple photon number states.
A method for operating a circuit quantum electrodynamic system, wherein, in paragraph 5, the first state is a superposition of two states having the same average number of photons.
In paragraph 6, the above-mentioned first state is, Given by class It is a nesting of, N and S are positive integers, and A method for operating a circuit quantum electrodynamic system representing the photon number state of n photons.
A method for operating a circuit quantum electrodynamic system according to claim 6, wherein the first state is a superposition of two states each having a first average number of photons, and the second state is a superposition of two states each having a second average number of photons different from the first average number of photons.
In paragraph 6, the first driving waveform and the second driving waveform are and A method for operating a circuit quantum electrodynamic system configured based on the value of
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the first driving waveform and the second driving waveform are selected from a computer-readable medium storing a plurality of previously determined driving waveforms.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the step of measuring the parity of each of the first state and the second state includes the step of measuring the photon number parity in base N, wherein N is an integer greater than 2.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the transition of the quantum mechanical oscillator from the second state back to the first state does not pass through the ground state of the quantum mechanical oscillator.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the quantum mechanical oscillator is a microwave cavity.
A method for operating a circuit quantum electrodynamic system, wherein, in claim 1, the physical qubit is a transmon qubit.
As a system, A circuit quantum electrodynamic system comprising physical qubits distributedly connected to a quantum mechanical oscillator; At least one computer-readable medium storing multiple driving waveforms; As at least one controller, Measure the parity of the first state of the above quantum mechanical oscillator; Subsequently, measuring the parity of the first state, measuring the parity of the second state of the quantum mechanical oscillator; and The at least one controller configured to select a first driving waveform and a second driving waveform among a plurality of stored driving waveforms based at least partially on the result of comparing the measured parity of the second state and the measured parity of the first state; and As at least one electromagnetic radiation source, Applying the above first driving waveform to the above quantum mechanical oscillator; and A system comprising at least one electromagnetic radiation source configured to apply the second driving waveform to the physical qubit simultaneously with the application of the first driving waveform.
A system according to claim 15, wherein the first driving waveform and the second driving waveform are configured based on the duration between measuring the parity of the first state and measuring the parity of the second state.
A system according to claim 15, wherein measuring the parity of each of the first state and the second state comprises measuring the photon number parity in binary.
A system according to paragraph 15, wherein measuring the parity of each of the first state and the second state includes measuring the photon number parity in base N, wherein N is an integer greater than 2.
A system according to claim 15, wherein the application of the first driving waveform and the second driving waveform is configured to transition the quantum mechanical oscillator from the second state back to the first state without passing through the ground state of the quantum mechanical oscillator.
In paragraph 15, the above quantum mechanical oscillator is a microwave cavity, a system.

Description

Techniques for quantum error correction using boson modes and related systems and methods Cross-reference regarding related applications This application claims priority to U.S. Provisional Application No. 62/263,473 (Title of invention: Quantum Error Correction Codes for Bosonic Modes, filing date: November 4, 2015), the subject matter of this basic application is incorporated by reference in its entirety. Statement on Government-Supported Research and Development The present invention received government support under 1122492 and 1301798 awarded by the National Science Foundation, FA9550-14-1-0052 and FA9550-15-1-0015 awarded by the United States Air Force Scientific Research Laboratory, and W911NF-14-1-0011 and W911NF-14-1-0563 awarded by the Office of the United States Military Research. The government holds specific rights to the present invention. Quantum information processing techniques perform output by manipulating one or more quantum objects. This technique is sometimes referred to as "quantum output." To perform output, quantum information processors utilize quantum objects to reliably store and retrieve information. According to some quantum information processing methods, a quantum analog to the classical output "bit" (equal to 1 or 0) is developed, which is referred to as a quantum bit, or "qubit." A qubit can consist of any quantum system that has two distinct states (which may be thought of as states 1 and 0), but also possesses the special property that the system can be placed in quantum superposition, allowing it to exist in both of these states at once. Several different types of qubits have been successfully demonstrated in the laboratory. However, the lifetime of the states in many of these systems is currently about ~100 μs, before information is lost due to quantum state decoherence or other quantum noise. Despite longer lifetimes, it may be important to provide error correction techniques for quantum computation that enable reliable storage and retrieval of information stored in the quantum system. However, unlike classical computation systems where bits can be copied for error correction purposes, it may be impossible to replicate the unknown states of a quantum system. Nevertheless, the system can become entangled with other quantum systems that effectively spread information within the system into several entangled objects. Some embodiments relate to a method for operating a circuit quantum electrodynamic system comprising physical qubits distributedly connected to a quantum mechanical oscillator, the method comprising the steps of measuring the parity of a first state of the quantum mechanical oscillator, and subsequently, measuring the parity of a second state of the quantum mechanical oscillator, wherein the second state is different from the first state, the method comprises the steps of applying a first driving waveform to the quantum mechanical oscillator, and simultaneously applying a second driving waveform to the physical qubit, wherein the first driving waveform and the second driving waveform are selected at least partially based on the result of comparing the measured parity of the second state with the measured parity of the first state, and the application of the first driving waveform and the second driving waveform transitions the quantum mechanical oscillator from the second state back to the first state, at least partially. According to some embodiments, the first state and the second state are superpositions of the same plurality of photon number states, and the first state and the second state have different amplitudes. According to some embodiments, the first driving waveform and the second driving waveform are configured based on the duration between the step of measuring the parity of the first state and the step of measuring the parity of the second state. According to some embodiments, the step of measuring the parity of each of the first state and the second state includes the step of measuring the photon number parity in binary. According to some embodiments, the first state is a superposition of multiple photon number states. According to some embodiments, the first state is a superposition of two states having the same average number of photons. According to some embodiments, the first state is Given by class It is a nesting of, and Here, N and S are positive integers, and represents the photon number state of n photons. According to some embodiments, the first state is a superposition of two states each having a first average number of photons, and the second state is a superposition of two states each having a second average number of photons different from the first average number of photons. According to some embodiments, the first driving waveform and the second driving waveform are and It is configured based on the value of. According to some embodiments, the first driving waveform and the second driving waveform are selected from a computer-re