Cryogenic Support Circuits and Systems for Silicon Quantum Computers

On the VCO/Frequency Divider Interface in Cryogenic CMOS PLL for Quantum Computing Applications

“…The PLL/PLO therefore appears to be an interesting candidate radiofrequency source for a quantum microprocessor [10,11]. A survey of the recent literature reveals that, under the pressure of packing together a large number of qubits, being the estimated goal for the quantum supremacy in the range of tens of millions, the actual envisage solution is moving the classical CMOS circuitry closer to the qubits by levering on the actual microelectronics technology [12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. The design of cryogenic CMOS circuitry for a quantum microprocessor is a real multi-faceted activity covering RFIC [12,17,22,24,26], DAC [16,24,26], readout circuits [22,25], and more general aspects related to the microprocessor architecture [15,23,25] and to the cryogenic system, as well.…”

“…microprocessor architecture [15,23,25] and to the cryogenic system, as well. This makes a quantum microprocessor closer to a mixed-signal than a pure digital circuit.…”

Cryogenic CMOS for Qubit Control and Readout

“…Non-CMOS devices, such as high-electron-mobility transistors (HEMTs), SiGe heterojunction bipolar transistors (HBTs), GaAs logic, and rapid single-flux quantum (RSFQ) circuits have been proposed to achieve high-performance circuit functionality of the type needed in the classical controller [8]- [10]. However, none of these technologies, except perhaps HBTs, can take advantage of 60 years of industrial development aimed at scalability, like CMOS [5][11] [12]. An advanced CMOS process, Intel 22nm FinFET technology, was selected in this work to implement complex functionality at low power.…”

Circuit-Based Compact Model of Electron Spin Qubit

“…Unlike the case of a traditional microprocessor, in which billions of transistors are packed in a silicon die but not singularly addressed, in a quantum processor, each single qubit should be addressable, making the interconnections a formidable obstacle, among, of course, other obstacles. Initially suggested by Reilly [16] and first investigated by Charbon et al [17], cryogenic CMOS integrated circuits seem to be a promising approach, because they make it possible to place the manipulation and read-out functionalities close to the qubits [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35]. These circuits include ADC, DAC, multiplexers, microwave oscillators, PLL, LNA, and mixers, making a quantum microprocessor similar to a mixed-signal circuit rather than to a purely digital circuitry.…”