Quantum computers (QC), comprising qubits and a classical controller, can provide exponential speed-up in solving certain problems. Among solid-state qubits, transmons and spin-qubits are the most promising, operating « 1K. A qubit can be implemented in a physical system with two distinct energy levels representing the |0) and |1) states, e.g. the up and down spin states of an electron. The qubit states can be manipulated with microwave pulses, whose frequency f matches the energy level spacing E = hf (Fig. 19.1.1). For transmons, f 6GHz, for spin qubits f20GHz, with the desire to lower it in the future. Qubit operations can be represented as rotations in the Bloch sphere. The rotation axis is set by the phase of the microwave signal relative to the qubit phase, which must be tracked for coherent operations. The pulse amplitude and duration determine the rotation angle. A π-rotation is typically obtained using a 50ns Gaussian pulse for transmons and a 500ns rectangular pulse for spin qubits with powers of -60dBm and -45dBm, respectively.

Original languageEnglish
Title of host publication2020 IEEE International Solid-State Circuits Conference, ISSCC 2020
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages3
ISBN (Electronic)9781728132044
Publication statusPublished - 2020
Event2020 IEEE International Solid-State Circuits Conference, ISSCC 2020 - San Francisco, United States
Duration: 16 Feb 202020 Feb 2020


Conference2020 IEEE International Solid-State Circuits Conference, ISSCC 2020
CountryUnited States
CitySan Francisco

ID: 72759219