An optical trap for laser cooling and trapping atoms. Three pairs of laser beams are directed to cross in a vacuum chamber at a common intersection volume, wherein each pair is formed by two counterpropagating beams. Rather than having a mutually orthogonal arrangement in which each beam pair forms an angle ? of 45? to a reference axis, z, these angles are instead between 5????40?. Moreover, in each beam pair, the counterpropagating beams are not precisely aligned in a common path, as in a conventional magneto-optical trap, but are slightly misaligned by respective misalignment angles [?, ?, ?] of typically 0.1? to 2?. The misalignment angles and beam widths are however selected so that a common intersection volume for all six beams is maintained. This provides an all-optical trap in which laser cooling and trapping of atoms takes place without a magnetic field being present.

An apparatus for driving atoms of an atom cloud into a targeted quantum state is provided, the apparatus comprising: an atom source for releasing a cloud of atoms to be driven into a targeted quantum state; a laser system configured to generate a laser beam to be directed onto the atom cloud in use, the laser beam having a frequency corresponding to a resonant frequency of an atomic transition for exciting the atoms into the targeted quantum state; a modulator configured to, in use, modulate the frequency of the laser beam responsive to an input signal; a waveform generator coupled to the modulator and configured to, in use, generate an input signal for the modulator, wherein the input signal is arranged to cause the modulator to modulate the laser light to generate a comb of frequencies around the resonant frequency of the atomic transition, the frequency comb including a plurality of peaks, each peak being separated by a frequency spacing, ??, that is determined based on a Rabi frequency, ?, of the atomic transition to drive atoms of the atom cloud into a targeted quantum state.

A particle trap system is provided, to resolve a problem of complex particle addressing in a conventional technology, and can be used in fields such as quantum computing. The particle trap system may include a trapping module, a first optical splitting module, and a first relative delay module. The trapping module is configured to trap at least two particles. The first optical splitting module is configured to split a received light beam into a first light beam and a second light beam. The first relative delay module is configured to adjust a delay amount for the first light beam and the second light beam to reach a first target particle, where an adjusted first light beam and an adjusted second light beam overlap at the first target particle, and the first target particle is at least one particle in the trapping module.

Fermions are the building blocks of matter. Here, we disclose a robust quantum register composed of hundreds of fermionic atom pairs trapped in an optical lattice. With each fermion pair forming a spin-singlet, the qubit is realized as a set of near-degenerate, symmetry-protected two-particle wavefunctions describing common and relative motion. Degeneracy is lifted by the atomic recoil energy, which depends on mass and lattice wavelength, thereby rendering two-fermion motional qubits insensitive to noise of the confining potential. The quantum coherence can last longer than ten seconds. Universal control is provided by modulating interactions between the atoms. Via state-dependent, coherent conversion of free atom pairs into tightly bound molecules, we tune the speed of motional entanglement over three orders of magnitude, yielding 10.sup.4 Ramsey oscillations within the coherence time. For site-resolved motional state readout, pairs are coherently split into their constituent fermions via a double-well, creating entangled Bell pairs.

A process for optically sorting a plurality of particles includes: providing a particle receiver; producing particles; receiving the particles by the particle receiver; receiving a light by the particle receiver; producing a standing wave optical interference pattern in an optical interference site of the particle receiver from the light; subjecting the particles to an optical gradient force from the standing wave optical interference pattern; deflecting the particles into a plurality of deflected paths to form the sorted particles from the particles; and propagating the sorted particles from the optical interference site through the deflected paths to optically sort the particles.

A system for atom interferometry includes one or more lasers disposed to 1) generate a first pair of beams that are initially spatially separated and later overlapped to follow a common path to intersecting an atomic cloud interaction region, wherein the first beam of the pair of beams acts as a first MOT beam and the second beam of the pair of beams acts as a first Raman beam; and 2) generate an additional beam, wherein the additional beam is multiplexed to be used alternately as a second MOT beam and as a second Raman beam, wherein the additional beam follows an opposing path to the common path when intersecting the atomic cloud interaction region.

A temporally continuous matter wave beam splitter (14) comprising a plurality of intersecting and interfering laser beam (k.sub.r, k.sub.b), which act as waveguides for a matter wave beam. The laser beams of the waveguides each have a frequency detuned below a frequency of an internal atomic transition of the matter wave. The matter wave has a wavevector which is an integral multiple of the wavevector of the laser beams within a region of intersection of the laser beams. There is also provided an atomic interferometer (200) comprising such a continuous matter wave beam splitter, and a solid state device comprising such a continuous matter wave beam splitter, which may be part of an atomic interferometer. A cold atom gyroscope, a cold atom accelerometer or a cold atom gravimeter comprising such a solid state device are also provided. There is further provided a quantum computer comprising such a solid state device, wherein atoms of the matter wave beam are in an entangled quantum state. There is also provided a method of splitting a matter wave beam, comprising introducing the matter wave beam into a first temporally continuous laser beam, the frequency of which is detuned below a frequency of an internal atomic transition of the matter wave beam; intersecting and interfering the first continuous laser beam with a second temporally continuous laser beam, the frequency of which is also detuned below the frequency of the internal atomic transition of the matter wave beam; providing the matter wave beam with a wavevector which is an integral multiple of the wavevector of the first and second laser beams within a region of intersection of the laser beams, whereby the laser beams act as waveguides for the matter wave beam.

In an aspect, the present disclosure provides a method comprising providing a first optical trap and a second optical trap, trapping an atom in the first optical trap, identifying a presence of the atom in the first optical trap, and transferring the atom from the first optical trap to the second optical trap.

Disclosed is a multi-dimensional optical tweezers calibration device based on electric field quantity calibration and a method thereof. The polarization-dependent characteristics of a tightly focused optical trap are utilized to realize triaxial electric field force calibration of particles through a one-dimensional electric field quantity calibration device. The method of the present application enables a particle electric field force calibration system to be compatible with particle delivery and particle detection systems; the device is simplified and calibration complexity is reduced.

A method of creating an optical atom trap comprises the steps of providing an incoherent light field with a light source apparatus, by creating a pulsed laser light beam of laser pulses with a repetition rate equal to or above 100 kHz and a relative spectral width of 10.sup.4 to 10.sup.2, coupling the pulsed laser light beam to an input end of a multimode waveguide device and guiding the pulsed laser light beam by total internal reflection to an output end of the multimode waveguide device, wherein the incoherent light field is provided at the output end, and creating the optical atom trap for trapping atoms in an atom trap chamber device by coupling the incoherent light field to the atom trap chamber device, wherein the optical atom trap has a trap frequency and the atoms have multiple resonance frequencies, and the laser pulses for providing the incoherent light field are created such that the repetition rate is above the trap frequency and the spectral width is below a spectral range between the resonance frequencies. Furthermore, an optical atom trap apparatus for optically trapping atoms is described.