公开(公告)号：US20230068284A1

公开(公告)日：2023-03-02

申请号：US18047792

申请日：2022-10-19

Applicant: International Business Machines Corporation

Inventor： Timothy Phung

IPC: H03K17/92 ,  G06N10/00 ,  G06F30/394 ,  H01L27/18

Abstract: Techniques for designing, creating, and utilizing a current biased tunable qubit are presented. A qubit device can comprise a first Josephson junction (JJ) located along a first current path of the device, and a second JJ and third JJ coupled in series along a second current path in parallel with the first current path, wherein the second and third JJs facilitate controlling frequency of the device. The first JJ can be larger in area than each of the second and third JJs, wherein a current splitting ratio between the first current path and second current path can be increased thereby. The device can comprise a capacitor with a first terminal associated with the second and third JJs, and a second terminal associated with ground. Alternatively, a high kinetic inductance wire can be used in the first current path, instead of the JJ.

公开(公告)号：US20220199886A1

公开(公告)日：2022-06-23

申请号：US17130376

申请日：2020-12-22

Applicant: International Business Machines Corporation

Inventor： Timothy Phung ,  David Abraham

IPC: H01L39/02 ,  H01L39/04 ,  H01L39/22 ,  H01L39/24 ,  G06N10/00

Abstract: Techniques for creating an offset embedded ground plane cutout for a qubit device to facilitate frequency tuning of the qubit device are presented. A qubit device can comprise a first substrate and second substrate in a flip-chip assembly. The qubit chip assembly can comprise a qubit component fabricated on the first substrate. The qubit component can comprise a Josephson junction (JJ) circuit that can be offset from a center point of the qubit component. The qubit chip assembly can comprise an embedded ground plane situated on a surface of the qubit chip assembly. A cutout section can be formed in the ground plane and positioned over the JJ circuit. The cutout section can enable access of an optical signal or magnetic flux to the JJ circuit. A frequency of the qubit component can be tuned based on application of the optical signal or magnetic flux to the JJ circuit.

公开(公告)号：US20220187388A1

公开(公告)日：2022-06-16

申请号：US17119519

申请日：2020-12-11

Applicant: International Business Machines Corporation

Inventor： Timothy Phung ,  Jiri Stehlik ,  Devin Underwood

IPC: G01R33/035 ,  H03H7/01 ,  H01P1/04

Abstract: Techniques for creating a low pass filter associated with a flux line are presented. A qubit device can comprise a first substrate and second substrate. A low pass filter, comprising at least one inductor and at least one capacitor can be formed, wherein respective components of or associated with the low pass filter can be formed on the first or second substrates, and wherein one or more bump bonds can extend between the substrates to connect respective components that are on respective substrates. The filter can receive an input signal via an input line and filter the signal to produce a filtered signal as output to a flux line that is in proximity to a coupler with SQUID loop and one or more flux-tunable qubits that are formed on one of the substrates. The filter can reduce electrical noise and Purcell decay associated with the flux line.

公开(公告)号：US20180039881A1

公开(公告)日：2018-02-08

申请号：US15228653

申请日：2016-08-04

Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION

Inventor： Martin M. Frank ,  Jin Ping Han ,  Masatoshi Ishii ,  Timothy Phung ,  Aakash Pushp

IPC: G06N3/063 ,  G06N3/04

CPC classification number: G06N3/0635 ,  G06N3/084

Abstract: A tunable resistance device and methods of forming the same include a magnetic fixed layer having a fixed magnetization, a magnetic free layer, and a non-magnetic conductive layer directly between the magnetic fixed layer and the magnetic free layer. The magnetic fixed layer, the magnetic free layer, and the non-magnetic conductive layer are formed in a lattice of wires, with each wire in the lattice being formed from a stack of the magnetic fixed layer, the magnetic free layer, and the non-magnetic conductive layer.

公开(公告)号：US09704551B2

公开(公告)日：2017-07-11

申请号：US14700015

申请日：2015-04-19

Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION

Inventor： Stuart S.P. Parkin ,  Timothy Phung ,  Aakash Pushp

IPC: G11C11/00 ,  G11C11/16 ,  G11C19/08

CPC classification number: G11C11/161 ,  G11C11/165 ,  G11C11/1675 ,  G11C19/0808

Abstract: Thermal-spin-torque (TST) in a magnetic tunnel junction (MTJ) is demonstrated by generating large temperature gradients across ultrathin MgO tunnel barriers, with this TST being significant enough to considerably affect the magnitude of the switching field of the MTJ. The origin of the TST is attributed to an asymmetry of the tunneling conductance across the zero-bias voltage of the MTJ. Through magneto-Seebeck voltage measurements, it is estimated that the charge-current that would be generated due to the temperature gradient would give rise to spin-transfer-torque (STT) that is a thousand times too small to account for the observed changes in switching fields, indicating the presence of large TST.

公开(公告)号：US09583212B2

公开(公告)日：2017-02-28

申请号：US14466904

申请日：2014-08-22

Applicant: INTERNATIONAL BUSINESS MACHINES CORPORATION

Inventor： Stuart P. Parkin ,  Timothy Phung ,  Aakash Pushp

IPC: H01L21/00 ,  G11C19/08

CPC classification number: G11C19/0808 ,  G11C11/161 ,  G11C11/1675 ,  G11C19/0841 ,  G11C19/0875

Abstract: A domain wall injector device uses electrical current passed across an interface between two magnetic regions whose magnetizations are aligned non-collinearly to create a domain wall or a series of domain walls in one of the magnetic regions. The method relies on a combination of innate fringing fields from the magnetic regions and the spin-transfer torque derived from the charge current. The device may be used to store data that are subsequently read out.

Abstract translation: 畴壁注射器装置使用通过两个磁性区域之间的界面的电流，其磁化非对称排列以在一个磁性区域中产生畴壁或一系列畴壁。 该方法依赖于来自磁性区域的固有边缘场和从充电电流导出的自旋传递扭矩的组合。 该设备可用于存储随后读出的数据。