内容：

Quantum computers bring in extraordinary capabilities at solving certain problems by taking classically inaccessible paths. A practical quantum computer will need a large number of qubits with good coherence and high fidelity control and measurement. In the superconducting circuit architecture, the transmon qubit is the most popular qubit design and is constructed as a single moderately anharmonic oscillator. In this talk, I will introduce a novel multi-modal circuit nicknamed trimon which implements a novel three-qubit circuit with always-on, all-to-all, longitudinal coupling [1]. This allows simple implementation of high fidelity three-qubit CCNOT gates. We demonstrate the universal programmability of this processor by implementing three-qubit versions of the Grover’s and period finding algorithm [2]. I will also discuss how to construct larger processors using the trimon as a three-qubit building block by adapting the well-known cross-resonance gate. 

[1] Tanay Roy et al.  Phys. Rev. Applied 7, 054025 (May 2017) 

[2] Tanay Roy et al., ArXiv:1809.00668 (2018)

人物介绍：

Dr. R. Vijay, Associate Professor, Tata Institute of Fundamental Research

Vijay completed his Bachelors degree in Physics from St. Stephen's College, Delhi University in 1999. He spent two more years at the University of Cambridge pursuing a BA in Natural Sciences before starting a PhD at Yale University in 2001. At Yale, he developed a new measurement technique for superconducting quantum bits. He continued work on improving quantum measurements during his postdoctoral work at the University of California, Berkeley which led to the first observation of quantum jumps and the first demonstration of quantum feedback in a solid state quantum system. In December 2012, Vijay returned to India and joined TIFR to start a new laboratory. He currently heads the Quantum Measurement and Control Laboratory where the main goal is to develop superior quantum processors and techniques to stabilize quantum states against decoherence. Some key highlights of this group's work include development of a broadband ultralow noise amplifier for quantum measurements and a novel multi-qubit processor design.