Abstract
This talk will cover practical challenges for cryogenic CMOS designs for next
generation quantum computing. Starting from system level, it will detail the design considerations
for a non-multiplexed, semi-autonomous, transmon qubit state controller (QSC) implemented in
14nm CMOS FinFET technology. The QSC includes an augmented general-purpose digital
processor that supports waveform generation and phase rotation operations combined with a low
power current-mode single sideband upconversion I/Q mixer-based RF arbitrary waveform
generator (AWG). Implemented in 14nm CMOS FinFET technology, the QSC generates control
signals in its target 4.5GHz to 5.5 GHz frequency range, achieving an SFDR > 50dB for a signal
bandwidth of 500MHz. With the controller operating in the 4K stage of a cryostat and connected
to a transmon qubit in the cryostat’s millikelvin stage, measured transmon T1 and T2 coherence
times were 75.5μS and 73μS, respectively, in each case comparable to results achieved using
conventional room temperature controls. In further tests with transmons, a qubit-limited error rate
of 7.76×10-4 per Clifford gate is achieved, again comparable to results achieved using room
temperature controls. The QSC’s maximum RF output power is -18 dBm, and power dissipation
per qubit under active control is 23mW.
Biography
Sudipto Chakraborty received his B. Tech from Indian Institute of Technology,
Kharagpur in 1998 and Ph.D in EE from Georgia Institute of Technology in 2002. He worked as
a researcher in Georgia Electronic Design Center (GEDC) till 2004. From 2004 to 2016, he was
a senior member of technical staff at Texas Instruments where he contributed to low power
integrated circuit design in more than 10 product families in the areas of automotive, wireless,
medical and microcontrollers. Since 2017, he has been working at the IBM T. J. Watson
Research Center where he leads the low power circuit design for next generation quantum
computing applications using nano CMOS technology nodes. He has authored or co-authored
more than 75 papers, two books and holds 87 US patents. He has served in the technical program
committees of various conferences including CICC, RFIC, IMS and has been elected as an IBM
master inventor in 2022 for his contributions.
Date & Time: Tuesday, November 28, 2023 from 17:00 – 18:30 Israel Time
Important: participation is free of charge but registration is required
For more details and updates on the series of “ACRC Semiconductor Webinars” please follow our newsletters and our website