Related papers: Optical Control of a Quantum Rotor
We analyze the control by electromagnetic fields of quantum systems with infinite dimensional Hilbert space and a discrete spectrum. Based on recent mathematical results, we rigorously show under which conditions such a system can be…
The quantum state of a flux qubit was successfully pulse-controlled by using a resonant microwave. We observed Ramsey fringes by applying a pair of phase-shifted pi/2 microwave pulses without introducing detuning. With this method, the…
We study quantum control of the full hyperfine manifold in the ground-electronic state of alkali atoms based on applied radio frequency and microwave fields. Such interactions should allow essentially decoherence-free dynamics and the…
Waveguide-based spin-photon interfaces on the GaAs platform have emerged as a promising system for a variety of quantum information applications directly integrated into planar photonic circuits. The coherent control of spin states in a…
The possibility to control the coherent decay of resonant excitations in nuclear forward scattering is investigated. By changing abruptly the direction of the nuclear hyperfine magnetic field, the coherent scattering of photons can be…
We study theoretically the dynamics of a a hybrid optomechanical system consisting of a macroscopic mechanical membrane magnetically coupled to a spinor Bose-Einstein condensate via a nanomagnet attached at the membrane center. We…
We propose a reliable scheme to simulate tunable and ultrastrong mixed (first-order and quadratic optomechanical couplings coexisting) optomechanical interactions in a coupled two-mode bosonic system, in which the two modes are coupled by a…
In traditional mechanics, harmonic oscillators can be used to measure force, acceleration, or rotation. Herein, we describe a quantum harmonic oscillator based on a penning trapped calcium ion crystal. Similar to traditional oscillators,…
Optical torque on individual atoms in a Bose-Einstein condensate can rotate the ensemble and generate a current flow [Phys. Rev. A 82, 051402 (2010)]. We exploit the fact to suggest a new mechanism for enhanced and well-controlled…
We observe cavity mediated spin-dependent interactions in an off-resonantly driven multi-level atomic Bose-Einstein condensate that is strongly coupled to an optical cavity. Applying a driving field with adjustable polarization, we identify…
We show that a Bose-Einstein condensate of heteronuclear molecules in the regime of small and static electric fields is described by a quantum rotor model for the macroscopic electric dipole moment of the molecular gas cloud. We solve this…
We theoretically study homogeneously trapped atomic Bose-Einstein condensates where all three momentum components couple to a pseudo-spin-$1/2$ degree of freedom. Tuning the anisotropies of spin-orbit coupling and the spin-dependent…
We propose and demonstrate the sequential initialization, optical control, and read-out of a single spin trapped in a semiconductor quantum dot. Hole spin preparation is achieved through ionization of a resonantly excited electron-hole…
Multi-electron semiconductor quantum dots have found wide application in qubits, where they enable readout and enhance polarizability. However, coherent control in such dots has typically been restricted to only the lowest two levels, and…
An optical resonator with intracavity Kerr nonlinearity can exhibit dispersive bistability suitable for all-optical switching. With nanophotonic elements it may be possible to achieve attojoule switching energies, which would be very…
We study the response of a Bose-Einstein condensate to an unbiased periodic driving potential. By controlling the space and time symmetries of the driving we show how a directed current can be induced, producing a coherent quantum ratchet.…
The coherent control of optical phonons has been experimentally demonstrated in various physical systems. While the transient dynamics for optical phonons can be explained by phenomenological models, the coherent control experiment cannot…
Quantum entanglement can provide enhanced precision beyond standard quantum limit (SQL), the highest precision achievable with classical means. It remains challenging, however, to observe large enhancement limited by the experimental…
We describe a coherent control technique for coupling electron spin states associated with semiconductor double-dot molecule to a microwave stripline resonator on a chip. We identify a novel regime of operation in which strong interaction…
Achieving coherent quantum control over massive mechanical resonators is a current research goal. Nano- and micromechanical devices can be coupled to a variety of systems, for example to single electrons by electrostatic or magnetic…