Back to results
US 12,748,905 B2Granted
Layouts for fault-tolerant quantum computers
AssigneeMicrosoft Technology Licensing, LLC
InventorsVadym Kliuchnikov, Nicolas Delfosse, Alexander Vaschillo
Life of this patent
Estimating the term…
Abstract
Disclosed herein are example layouts and layout generation techniques for fault-tolerant quantum computers. Example embodiments comprise methods for performing a layout reduction technique for fault-tolerant quantum computing. In certain embodiments, a layout of an arbitrary quantum circuit is reduced to a layout of exponents of a multiple qubit Pauli matrix and measurements of a multiple qubit Pauli matrix. In certain embodiments, qubits are marked as one of a data, interface, or ancilla qubit for a 2D nearest neighbor graph of qubit connectivity, and an ancilla-path is provided from a respective data qubit to a respective interface qubit.
Claims7
A system, comprising:
- a quantum computer;
- and
- one or more classical-computing devices, at least some of the one or more classical computing devices being programmed to
- transform a quantum computation of the form
- C
- 2
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- exp
-
- (
- i
-
- ϕZ
- i
-
- (
- 1
- )
- )
-
- C
- 0
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- to a sequence of exponentials and measurements of the form:
- M
-
- (
- a
- ,
- P
- 2
- )
-
- exp
-
- (
- i
-
- ϕ
-
- P
- 1
- )
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- in which P1 and P2 are multiple qubit Pauli operators,
- M(a,P2)=(I+aP2)/2 denotes measurement of the multiple qubit Pauli operator P2 with outcome a=±1, wherein/is the identity matrix, wherein
- P
- 1
- =
- C
- 0
- T
-
- Z
- i
-
- (
- 1
- )
- )
-
- C
- 0
- ,
- and
-
- P
- 2
- =
- (
- C
- 1
-
- C
- 0
- )
- †
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- C
- 0
- ,
- construct a tree (V,E) with root node r∈V, the tree describing a 2D grid of qubits in which each vertex V describes a qubit in the 2D grid, and vertices describing nearest neighbor qubits in the 2D grid are connected by an edge in E;
- and
- configure the quantum computer comprising the 2D grid of qubits to implement the sequence of exponentials and measurements using:
- one-qubit measurements and one-qubit Clifford unitaries,
- either (A) controlled Z-gates or (B) two-qubit measurements on nearest neighbor qubits described by vertices connected by an edge in E, (A) or (B) being used to perform multi-target controlled Z-gates and each Clifford C and C† such that CZrC†=P being constructed using multi-target controlled Z-gates, and
- single qubit rotations that are only performed on the qubits described by the root node r.
128 more elements
One or more classical-computer-readable-media storing classical-computer-executable instructions, which when executed by a classical computer cause the classical computer to
- transform a quantum computation of the form
- C
- 2
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- exp
-
- (
- i
-
- ϕZ
- i
-
- (
- 1
- )
- )
-
- C
- 0
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- to a sequence of exponentials and measurements of the form:
- M
-
- (
- a
- ,
- P
- 2
- )
-
- exp
-
- (
- i
-
- ϕ
-
- P
- 1
- )
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- in which P1 and P2 are multiple qubit Pauli operators,
- M(a,P2)=(I+aP2)/2 denotes measurement of the multiple qubit Pauli operator P2 with outcome a=±1, wherein I is the identity matrix, wherein
- P
- 1
- =
- C
- 0
- T
-
- Z
- i
-
- (
- 1
- )
- )
-
- C
- 0
- ,
- and
-
- P
- 2
- =
- (
- C
- 1
-
- C
- 0
- )
- †
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- C
- 0
- ,
- construct a tree (V,E) with root node r∈V, the tree describing a 2D grid of qubits in which each vertex V describes a qubit in the 2D grid, and vertices describing nearest neighbor qubits in the 2D grid are connected by an edge in E;
- and
- configure the quantum computer comprising the 2D grid of qubits to implement the sequence of exponentials and measurements using:
- one-qubit measurements and one-qubit Clifford unitaries,
- either (A) controlled Z-gates or (B) two-qubit measurements on nearest neighbor qubits described by vertices connected by an edge in E, (A) or (B) being used to perform multi-target controlled Z-gates and each Clifford C and C† such that CZrC†=P being constructed using multi-target controlled Z-gates, and
- single qubit rotations that are only performed on the qubits described by the root node r.
125 more elements
A method performed by one or more classical computing devices, comprising:
- transforming a quantum computation of the form
- C
- 2
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- exp
-
- (
- i
-
- ϕZ
- i
-
- (
- 1
- )
- )
-
- C
- 0
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- to a sequence of exponentials and measurements of the form:
- M
-
- (
- a
- ,
- P
- 2
- )
-
- exp
-
- (
- i
-
- ϕ
-
- P
- 1
- )
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- in which P1 and P2 are multiple qubit Pauli operators, M(a,P2)=(I+aP2)/2 denotes measurement of the multiple qubit Pauli operator P2 with outcome a=±1, wherein I is the identity matrix, wherein
- P
- 1
- =
- C
- 0
- T
-
- Z
- i
-
- (
- 1
- )
- )
-
- C
- 0
- ,
- and
-
- P
- 2
- =
- (
- C
- 1
-
- C
- 0
- )
- †
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- C
- 0
- ,
- constructing a tree (V,E) with root node r∈V, the tree describing a 2D grid of qubits in which each vertex V describes a qubit in the 2D grid, and vertices describing nearest neighbor qubits in the 2D grid are connected by an edge in E;
- and
- configuring a quantum computer comprising the 2D grid of qubits to implement the sequence of exponentials and measurements using:
- one-qubit measurements and one-qubit Clifford unitaries,
- either (A) controlled Z-gates or (B) two-qubit measurements on nearest neighbor qubits described by vertices connected by an edge in E, (A) or (B) being used to perform multi-target controlled Z-gates and each Clifford C and C† such that CZrC†=P being constructed using multi-target controlled Z-gates, and
- single qubit rotations that are only performed on the qubits described by the root node r.
124 more elements
A system, comprising:
- a quantum computer;
- and
- one or more classical-computing devices, at least some of the one or more classical computing devices being programmed to:
- transform a quantum computation of the form
- C
- 2
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- exp
-
- (
- i
-
- ϕZ
- i
-
- (
- 1
- )
- )
-
- C
- 0
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- to a sequence of exponentials and measurements of the form:
- M
-
- (
- a
- ,
- P
- 2
- )
-
- exp
-
- (
- i
-
- ϕ
-
- P
- 1
- )
-
- ❘
- "\[LeftBracketingBar]"
- 0
- 〉
- ⊗
- n
- in which P1 and P2 are multiple qubit Pauli operators,
- M(a,P2)=(1+aP2)/2 denotes measurement of the multiple qubit Pauli operator P2 with outcome a=±1, wherein I is the identity matrix, wherein
- P
- 1
- =
- C
- 0
- T
-
- Z
- i
-
- (
- 1
- )
- )
-
- C
- 0
- ,
- and
-
- P
- 2
- =
- (
- C
- 1
-
- C
- 0
- )
- †
-
- M
-
- (
- a
- ,
- Z
- i
-
- (
- 2
- )
- )
-
- C
- 1
-
- C
- 0
- ,
- construct a tree (V,E) with root node r∈V, the tree describing a 2D grid of qubits in which each vertex V describes a qubit in the 2D grid, and vertices describing nearest neighbor qubits in the 2D grid are connected by an edge in E;
- and
- configure the quantum computer comprising the 2D grid of qubits to implement the sequence of exponentials and measurements using:
- one-qubit measurements and one-qubit Clifford unitaries,
- either (A) controlled Z-gates or (B) two-qubit measurements on nearest neighbor qubits described by vertices connected by an edge in E, (A) or (B) being used to perform multi-target controlled Z-gates and each Clifford C and C† such that CZrC†=P being constructed using multi-target controlled Z-gates, and
- single qubit rotations that are only performed on the qubits described by the root node r, wherein qubits of the quantum computer comprise data qubits, interface qubits, and ancilla qubits and a graph of qubit connectivity satisfies a condition of providing an ancilla-path from one or more data qubits to the interface qubits.
128 more elements
Dependencies are inferred from the claim text.