# US 12,762,444 B2 · Generation of N-body entangling interactions between qubits

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,762,444 B2
- Document ID: US12762444B2
- Status: Granted
- Kind: B2
- Application number: 18/059,550
- Filed: 2022-11-29
- Published: 2023-06-22
- Granted: 2026-10-13
- Earliest claimed: 2021-11-29
- Assignees: Duke University
- Applicants: Duke University
- Inventors: Christopher Monroe; Or Katz; Marko Cetina
- Web page: https://patentgrep.com/patent/US12762444B2

## CPC

- G06N 10/20: Models of quantum computing, e.g. quantum circuits or universal quantum computers
- G01R 33/0029: {Treating the measured signals, e.g. removing offset or noise}
- G01R 33/1284: {Spin resolved measurements; Influencing spins during measurements, e.g. in spintronics devices}
- G06N 10/00: Quantum computing, i.e. information processing based on quantum-mechanical phenomena
- G06N: COMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
- G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12)

## Abstract

Systems and methods for producing N-body entangling interactions to simplify n-gate operations in quantum computing applications are disclosed herein. According to at least some embodiments, an oscillator generates a two-tone field tuned to qubit resonance, first upper motion-induced sidebands, first lower motion-induced sidebands, second upper motion-induced sidebands, and second lower motion-induced sidebands.

## Claims

### Claim 1

A method for generating an N-body entangling interaction between qubits in a quantum computing system, comprising:
configuring one or more parameters for each of a plurality of pulses to be individually applied to a plurality of target ions in a chain of trapped ions as a series of displacement operations and qubit state-dependent squeezing operations on each of the target ions, each of the trapped ions in the chain defining one of the qubits of the quantum computing system, wherein each of the displacement operations and the qubit state-dependent squeezing operations occur in a specified sequence;
generating, based on the one or more parameters, each of the plurality of pulses; and
applying the generated pulses to the plurality of target ions to create an entanglement interaction between the target ions.

### Claim 2 (depends on 1)

The method of claim 1, wherein configuring the one or more parameters comprises configuring a tuning frequency and amplitude of the pulses to drive one or more properties associated with each of the target ions.

### Claim 3 (depends on 2)

The method of claim 2, wherein to drive the one or more properties associated with each of the target ions comprises to drive a quantum state of the respective qubit.

### Claim 4 (depends on 2)

The method of claim 2, wherein to drive the one or more properties associated with each of the target ions comprises to drive a motion of the respective qubit.

### Claim 5 (depends on 2)

The method of claim 2, wherein to drive the one or more properties associated with each of the target ions comprises to drive motional transitions for generating the series of displacement and qubit state-dependent squeezing operations.

### Claim 6 (depends on 1)

The method of claim 1, wherein each of the displacement operations occurs simultaneously with each of the qubit state-dependent squeezing operations.

### Claim 7 (depends on 1)

The method of claim 1, wherein each of the displacement operations occur in a sequential and interleaved manner relative to the qubit state-dependent squeezing operations.

### Claim 8 (depends on 1)

The method of claim 1, wherein the displacement operations are qubit state-dependent.

### Claim 9

A method for generating an N-body entangling interaction between two or more target qubits of a plurality of qubits in a quantum computing system, comprising:
generating, by an oscillator of the computing system and for each target, a plurality of a single-tone or multi-tone fields, a first field driving the qubit between its quantum states, a second field driving the motion of the qubit, a third field driving first motional sidebands of the qubit, and a fourth field driving second motional sidebands of the qubit to apply a series of displacement forces and qubit state-dependent squeezing forces on the qubit to entangle the qubit with the other target qubits.

### Claim 10 (depends on 9)

The method of claim 9, wherein the application of the displacement forces occurs simultaneously with the application of the qubit state-dependent squeezing forces.

### Claim 11 (depends on 9)

The method of claim 9, wherein the application of displacement forces and qubit state-dependent squeezing forces occur in an interleaved manner within one another.

### Claim 12 (depends on 9)

The method of claim 9, wherein the displacement forces are determined based on HD=ℏA(x sin φD+p cos φD) and wherein the squeezing forces are determined based on HS=(e−iδφ{circumflex over (α)}2−eiδφ{circumflex over (α)}†2).

### Claim 13

A quantum computing system, comprising:
one or more processors;
a chain of trapped ions, each of the trapped ions defining a qubit;
one or more lasers configured to emit a laser beam that is split into two or more non-copropagating laser beams which are provided to each of the trapped ions;
a controller comprising memory storing program code, which, when executed by the one or more processors, causes the quantum computing system to:
configure one or more parameters for each of a plurality of pulses to be individually applied to a plurality of target ions in a chain of trapped ions as a series of displacement operations and qubit state-dependent squeezing operations on each of the target ions, each of the trapped ions in the chain defining one of the qubits of the quantum computing system;
generate, based on the one or more parameters, each of the plurality of pulses; and
apply the generated pulses to the plurality of target ions to create an entanglement interaction between the target ions.

### Claim 14 (depends on 13)

The quantum computing system of claim 13, wherein to configure the one or more parameters comprises to configure a tuning frequency and amplitude of the pulses to drive one or more properties associated with each of the target ions.

### Claim 15 (depends on 14)

The quantum computing system of claim 14, wherein to drive the one or more properties associated with each of the target ions comprises to drive a quantum state and/or a motion of the respective qubit.

### Claim 16 (depends on 14)

The quantum computing system of claim 14, wherein to drive the one or more properties associated with each of the target ions comprises to drive motional transitions for generating the series of displacement and spin-dependent qubit state-dependent squeezing operations.

### Claim 17 (depends on 13)

The quantum computing system of claim 13, wherein each of the displacement operations occurs simultaneously with each of the qubit state-dependent squeezing operations.

### Claim 18 (depends on 13)

The quantum computing system of claim 13, wherein each of the displacement operations and the qubit state-dependent squeezing operations occur in a specified sequence.

### Claim 19 (depends on 13)

The quantum computing system of claim 13, wherein each of the displacement operations occur in a sequential and interleaved manner relative to the qubit state-dependent squeezing operations.