Shiqian Ding

Quantum absorption refrigerator with trapped ions

A remarkable progress has recently been achieved in studies of thermodynamics and heat machines, with experiments probing down to micro and nano-scale systems such as the single Brownian particle [1], as well as the single atom [2]. However, despite several theoretical proposals [3, 4], implementation of heat machines in the fully quantum regime remains a challenge. We report on an experimental realization of a quantum absorption refrigerator in a system of the three trapped 171Yb+ ions. The normal modes of motion are coupled by a trilinear Hamiltonian ab†c† and represent “hot”, “work” and “cold” bodies of the refrigerator (Figure 1). We investigate the equilibrium properties of the refrigerator, and demonstrate the absorption refrigeration effect with the modes being prepared in thermal states.

Microwave control of trapped-ion motion assisted by a running optical lattice.

We experimentally demonstrate microwave control of the motional state of a trapped ion placed in a state-dependent potential generated by a running optical lattice. Both the optical lattice depth and the running lattice frequency provide tunability of the spin-motion coupling strength. The spin-motional coupling is exploited to demonstrate sideband cooling of a ^{171}Yb^{+} ion to the ground state of motion.

Phonon-phonon interactions in a linear ion trap

We observe nonlinear coupling of phonons between radial and axial directions in a system of two ions in a linear Paul trap. Anticrossing of phonon modes and adiabatic energy transfer are demonstrated.

Zeeman-Splitting-Assisted Quantum Logic Spectroscopy of Trapped Ions

We present a quantum logic scheme to detect atomic and molecular ions in different states of angular momentum based on their magnetic

A quantum parametric oscillator with trapped ions

g

Cross-Kerr Nonlinearity for Phonon Counting

factors. The state-dependent magnetic

3-D Magneto-Optical Trap of Yttrium Monoxide.

g

Quantum Simulation with a Trilinear Hamiltonian

factors mean that electronic, rotational, or hyperfine states may be distinguished by their Zeeman splittings in a given magnetic field. Driving motional sidebands of a chosen Zeeman splitting enables reading out the corresponding state of angular momentum with an auxiliary logic ion. As a proof-of-principle demonstration, we show that we can detect the ground electronic state of a

YO laser cooling and trapping with an improved repumping scheme

^{174}\mathrm{Yb}^{+}

Applications of the trilinear Hamiltonian with three trapped ions

ion using