On the Phase Controlled Qubit State Measurement Using Analog Microwave Phase Shifter

Jan 1, 0001

Superconducting quantum circuits are the most popular solid-state system used to implement quantum computation. Their computational units, the superconducting qubits, are micro-fabricated on substrates using thin-film deposition techniques similar to typical integrated circuits. The control and measurements of these qubits rely on waveguides microwave fields with techniques similar to those for millimeter-wave analog circuitry, where the output signal phase relative to the input plays a crucial role in determining the quantum state. A controllable phase to align the carrier and the amplitude envelope thus becomes essential. In this work, we implement a microwave phase shifter with 1 GHz bandwidth about the 4.75 GHz center frequency in conjunction with standard microwave equipment to measure a qubit.

The traditional signal modulation and phase shifted modulation setup shown in (a) and (b), respectively. The experimental setup, design layout, and effective circuit of the phase comparator are shown in this figure.
The traditional signal modulation and phase shifted modulation setup shown in (a) and (b), respectively. The experimental setup, design layout, and effective circuit of the phase comparator are shown in this figure.
Quantum Computing
Jiheng Duan 段繼恆
Jiheng Duan 段繼恆
First year PhD student

My research interests include superconducting quantum computing, high fidelity two-qubit gate, and distortion correction of digital signals.