Distinguished Quantum Colloquium - Dr. Yiwen Chu

The quantum world of massive mechanical objects

One of the first model systems we encounter in quantum mechanics class is a mass on a spring. However, in practice, it is not easy to observe a massive mechanical object exhibiting the quantum properties of a harmonic oscillator, such as zero-point fluctuations, energy quantization, or quantum superpositions. Nevertheless, in recent years, it has become possible to control and measure the quantum states of the motion of macroscopic mechanical objects. I will present our recent experiments on creating “Schrödinger cat” states in a bulk acoustic wave resonator by coupling it to a superconducting circuit and how we can observe the quantum ground state of a several hundred microgram mechanical mode using light. I will also discuss the applications of these systems in quantum information, quantum sensing, and explorations of fundamental physics.