公开(公告)号：US20170372218A1

公开(公告)日：2017-12-28

申请号：US15631548

申请日：2017-06-23

Applicant: HITACHI, LTD.

Inventor： Aleksey ANDREEV ,  David WILLIAMS

IPC: G06N99/00

CPC classification number: G06N99/002

Abstract: A method of reducing quantum leakage in a qubit device is disclosed. The method comprises receiving a set of energy level values for a multi-level system which includes first and second working levels |0>, |1> which provide a qubit and at least one other level |2> and performing an iteration at least once. the iteration comprising determining quantum leakage from at least one of the first and second working levels to the at least one non-working level for a quantum operation A comprising at least one pulse wherein each pulse has a respective pulse duration, determining whether the quantum leakage is greater than or equal to a threshold value; and, in dependence on the quantum leakage being greater than or equal to the threshold value, changing the duration of at least one of the at least one pulse.

公开(公告)号：US20170288076A1

公开(公告)日：2017-10-05

申请号：US15442113

申请日：2017-02-24

Applicant: HITACHI, LTD.

Inventor： Aleksey ANDREEV ,  David WILLIAMS ,  Ryuta TSUCHIYA ,  Yuji SUWA

IPC: H01L31/0352 ,  H01L29/06 ,  H01L31/024 ,  G06N99/00 ,  H01L33/34 ,  H01L33/64 ,  H01L31/112 ,  H01L33/00 ,  H01L31/028 ,  H01L33/06

CPC classification number: H01L31/035218 ,  B82Y10/00 ,  B82Y15/00 ,  B82Y20/00 ,  B82Y30/00 ,  G06N99/002 ,  H01L29/0649 ,  H01L29/127 ,  H01L29/66977 ,  H01L29/7613 ,  H01L31/024 ,  H01L31/028 ,  H01L31/112 ,  H01L33/0041 ,  H01L33/06 ,  H01L33/34 ,  H01L33/64 ,  Y10S977/774 ,  Y10S977/814 ,  Y10S977/933 ,  Y10S977/95 ,  Y10S977/954

Abstract: A silicon-based quantum dot device (1) is disclosed. The device comprises a substrate (8) and a layer (7) of silicon or silicon-germanium supported on the substrate which is configured to provide at least one quantum dot (51, 52: FIG. 5). The layer of silicon or silicon-germanium has a thickness of no more than ten monolayers. The layer of silicon or silicon-germanium may have a thickness of no more than eight or five monolayers.