Ramsey interferometry with trapped motional quantum states

Abstract

Ramsey interferometers (RIs) using internal electronic or nuclear states find wide applications in science and engineering. We develop a matter wave Ramsey interferometer for motional quantum states exploiting the S-and D-bands of an optical lattice and identify the different de-phasing and de-coherence mechanisms. We implement a band echo technique, employing repeated π-pulses. This suppresses the de-phasing evolution and significantly increase the coherence time of the motional state interferometer by one order of magnitude. We identify thermal fluctuations as the main mechanism for the remaining decay contrast. Our demonstration of an echo-Ramsey interferometer with motional quantum states in an optical lattice has potential application in the study of quantum many body lattice dynamics, and motional qubits manipulation.

Asymmetric population of momentum distribution by quasi-periodically driving a triangular optical lattice

“…Ultracold atom systems provide us unique opportunity to investigate the interaction between atoms and light [1,2], quantum many-body problems [3,4], quantum precise metrology [5,6], etc. Since the experimental realization of Bose-Einstein Condensate (BEC) [7,8], numerous works have been carried out to optimize the BEC [9], extract and eliminate noise pattern [10,11] and build up atom interferometry [12,13] and so on. Particularly, by forming certain interference pattern of laser beams, people could set up optical lattice (OL) systems, which provide us much insight into the condensed matter physics [14][15][16][17].…”

Nonlinear emergent elasticity and structural transitions of a skyrmion crystal under uniaxial distortion

“…(5) by setting all components of elastic strains to zero except ε 11 . For deformable hexagonal 2-D emergent crystals, the rescaled magnetization m can be described mathematically as a Fourier series [48]:…”

“…where m is the rescaled magnetization, ε 11 is the strain component describing the uniaxial distortion, t is the rescaled temperature, b is the rescaled magnetic field, and w 0 denotes the part of free energy density independent of the magnetization. To describe the deformed SkX, m is expanded within the n th order Fourier representation as [42,48]…”

“…Concerning the large number of variables included in m a and ε ea , the minimization problem is solved numerically. To guarantee that the solution obtained actually corresponds to a local minimum of the free energy of the system, the method of soft-mode analysis [48] is incorporated in the minimization process.…”

Finite temperature phase transition in a cross-dimensional triangular lattice

“…We have a harmonic trap with frequencies (ω x , ω y , ω z )=2π × (24 Hz, 48 Hz, 55 Hz) in the three directions, respectively. The procedure details have been provided in our earlier works [48][49][50][51][52]. After the preparation of BECs, we adiabatically ramp on the triangular lattice within 80 ms. Then the vertical lattice V z is adiabatically turned on within 20 ms. Then we hold the system for 10 ms.…”