公开(公告)号：US20210272008A1

公开(公告)日：2021-09-02

申请号：US17188461

申请日：2021-03-01

Applicant: Massachusetts Institute of Technology ,  SOCPRA SCIENCES ET GENIE S.E.C.

Inventor： William D. OLIVER ,  Simon GUSTAVSSON ,  Roni WINIK ,  Catherine LEROUX ,  Agustin DI PAOLO ,  Alexandre BLAIS

IPC: G06N10/00 ,  H01L39/02 ,  H01L39/22

Abstract: A quantum circuit called a “qumon” is provided to cancel unwanted ZZ interaction in a superconducting qubit architecture. The qumon qubit has a high coherence, and a positive anharmonicity that may be tuned to cancel the negative anharmonicity in a coupled qubit, such as a transmon qubit. The qumon has three parallel branches, in which are a shunt capacitor; a Josephson junction having weighted energy level and capacitance; and several Josephson junctions in series. The weight is chosen to provide the desired anharmonicity, and the transverse flux noise and transverse charge noise each decrease in proportion to the number of the Josephson junctions in series. Because unwanted ZZ interactions are canceled, qumon qubits and transmon qubits may be capacitively coupled in an alternating pattern to provide a surface code in which these interactions are canceled in an extensible way.

公开(公告)号：US20230142623A1

公开(公告)日：2023-05-11

申请号：US17673259

申请日：2022-02-16

Applicant: SOCPRA SCIENCES ET GENIE S.E.C.

Inventor： Catherine LEROUX ,  Agustin DI PAOLO ,  Alexandre BLAIS

IPC: G06N10/20 ,  G06F15/82

CPC classification number: G06N10/20 ,  G06F15/82

Abstract: The generally quantum system can have : a first quantum subsystem having a first set of eigenstates; a second quantum subsystem having a second set of eigenstates; a coupler connected to both the first quantum system and to the second quantum system, the coupler having a third set of eigenstates; at least one interaction drive configured to control interaction between the first set of eigenstates and the second set of eigenstates via transitions within the third set of eigenstates; an auxiliary quantum subsystem connected to the coupler; and an attenuation drive selectively operable at a drive amplitude to generate a set of stabilized states in the auxiliary quantum system, said set of stabilized states being entangled with the third set of eigenstates in a manner that the probability of said transition within the third set of eigenstates is set by a probability of transition in the set of stabilized states.

公开(公告)号：US20240346350A1

公开(公告)日：2024-10-17

申请号：US18048574

申请日：2022-10-21

Applicant: Massachusetts Institute of Technology ,  SOCPRA SCIENCES ET GENIE S.E.C., A/S TransferTech Sherbrooke

Inventor： Augustin DI PAOLO ,  William D. OLIVER ,  Catherine LEROUX ,  Alexandre BLAIS

IPC: G06N10/40 ,  H10N60/12

CPC classification number: G06N10/40 ,  H10N60/12

Abstract: A system and method provide two-qubit gates and quantum computing circuits built therefrom. Pairs of qubits are inductively or capacitively coupled using a coupler that is driven using an off-resonant microwave drive. By controlling the drive, the ZZ interaction between the qubits can be precisely controlled. In particular, the interaction may be selectively reduced or suppressed, thereby isolating the qubits from each other, or the interaction may be increased to provide fast, controlled-Z, two-qubit gates with high fidelity. Moreover, qubits and couplers may be arranged according to their resonant frequencies into unit cells and replicated to arbitrary size, thereby forming a quantum computer.