arXiv subjects

Jerzy Zachorowski

Publications and source records attributed to Jerzy Zachorowski.

9 recordsLinked to original sources

arXiv2015

Absolute measurement of the ${}^{1}S_{0}$ - ${}^{3}P_{0}$ clock transition in neutral ${}^{88}$Sr over the 330 km-long stabilized fibre optic link

We report a stability below $7\times 10{}^{-17}$ of two independent optical lattice clocks operating with bosonic ${}^{88}$Sr isotope. The value (429228066418008.3(1.9)${}_{syst}$(0.9)${}_{stat}$~Hz) of the absolute frequency of the ${}^{1}S_{0}$ - ${}^{3}P_{0}$ transition was measured with an optical frequency comb referenced to the local representation of the UTC by the 330 km-long stabilized fibre optical link. The result was verified by series of measurements on two independent optical lattice clocks and agrees with recommendation of Bureau International des Poids et Mesures.

physics.atom-ph↗

arXiv2013

Matter-Wave Interference versus Spontaneous Pattern Formation in Spinor Bose-Einstein Condensate

We describe effects of matter-wave interference of spinor states in the $^{87}$Rb Bose-Einstein condensate. The components of the F=2 manifold are populated by forced Majorana transitions and then fall freely due to gravity in an applied magnetic field. Weak inhomogeneities of the magnetic field, present in the experiment, impose relative velocities onto different $m_F$ components, which show up as interference patterns upon measurement of atomic density distributions with a Stern-Gerlach imaging method. We show that interference effects may appear in experiments even if gradients of the magnetic field components are eliminated but higher order inhomogeneity is present and the duration of the interaction is long enough. In particular, we show that the resulting matter-wave interference patterns can mimic spontaneous pattern formation in the quantum gas.

cond-mat.quant-gas↗

arXiv2012

Modeling an optical magnetometer with electronic circuits - Analysis and optimization

Optical magnetometers are currently able to achieve magnetometric sensitivities below 1 fT/Hz^1/2. Although such sensitivities are typically obtained for ultra-low-field measurements, a group of optical magnetometers allows the detection of the fields in much broader dynamic range without a significant compromise in the sensitivity. A particular example of such a device is the magnetometer exploiting amplitude-modulated nonlinear magneto-optical rotation. It enables to measure a magnetic field via detection of a polarization state of light traversing a medium subjected to the field. In this paper, an electronic-circuit analogue of such the magnetometer is elaborated. Its operation is investigated with an electronic-circuit design software, which allows to study the "magnetometer" performance as a function of various parameters. The ability to automate operation of the magnetometer and automatically track "magnetic field" is demonstrated. The simulations are verified with experimental results obtained with the magnetometer operating in one of the investigated arrangements.

physics.atom-ph↗

arXiv2010

Designing Zeeman slower for strontium atoms - towards optical atomic clock

We report on design and construction of a Zeeman slower for strontium atoms which will be used in an optical atomic clock experiment. The paper describes briefly required specifications of the device, possible solutions, and concentrates on the chosen design. The magnetic field produced by the built Zeeman slower has been measured and compared with the simulations. The system consisting of an oven and Zeeman slower are designed to produce an atomic beam of 10-12 s-1 flux and final velocity of ~30 m/s.

physics.atom-ph↗

arXiv2010

Nonlinear Faraday Rotation and Superposition-State Detection in Cold Atoms

We report on the first observation of nonlinear Faraday rotation with cold atoms at a temperature of ~100 uK. The observed nonlinear rotation of the light polarization plane is up to 0.1 rad over the 1 mm size atomic cloud in approximately 10 mG magnetic field. The nonlinearity of rotation results from long-lived coherence of ground-state Zeeman sublevels created by a near-resonant light. The method allows for creation, detection and control of atomic superposition states. It also allows applications for precision magnetometry with high spatial and temporal resolution.

physics.atom-ph↗

arXiv2008

Optimal geometry for efficient loading of an optical dipole trap

One important factor which determines efficiency of loading cold atoms into an optical dipole trap from a magneto-optical trap is the distance between the trap centers. By studying this efficiency for various optical trap depths (2--110 mK) we find that for optimum dipole trap loading, longitudinal displacements up to 15 mm are necessary. An explanation for this observation is presented and compared with other work and a simple analytical formula is derived for the optimum distance between the trap centers.

physics.atom-ph↗

arXiv2006

Bound and free atoms diagnosed by the recoil-induced resonances: 1D optical lattice in a working MOT

We report on studies of simultaneous trapping of $^{85}$Rb atoms in a magneto-optical trap (MOT) and 1D optical lattice. Using Raman pump-probe spectroscopy we observe the coexistence of two atomic fractions: the first, which consists of free, unbound atoms trapped in a MOT and the second, localized in the micropotentials of the optical lattice. We show that recoil-induced resonances allow not only temperature determination of the atomic cloud but, together with vibrational resonances, can also be used for real-time, nondestructive studies of the lattice loading and of the dynamics of systems comprising unbound and bound atomic fractions.

physics.atom-ph↗

arXiv2005

Non-destructive study of non-equilibrium states of cold, trapped atoms

Highly sensitive, non-destructive, real-time spectroscopic determination of the 2D kinetic momentum distribution of a cold-atom sample is performed with the three-beam measurement of the recoil-induced resonances. The measurements performed with an operating magneto-optical trap reveal slow velocity drifts within a stationary atomic cloud and strong anisotropy and asymmetry of the non-Maxwellian momentum distribution. The developed method can be easily extended to 3D.

physics.atom-ph↗

arXiv2004

Probe spectroscopy in an operating magneto-optical trap: the role of Raman transitions between discrete and continuum atomic states

We report on cw measurements of probe beam absorption and four-wave-mixing spectra in a $^{85}$Rb magneto-optical trap taken while the trap is in operation. The trapping beams are used as pump light. We concentrate on the central feature of the spectra at small pump-probe detuning and attribute its narrow resonant structures to the superposition of Raman transitions between light-shifted sublevels of the ground atomic state and to atomic recoil processes. These two contributions have different dependencies on trap parameters and we show that the former is inhomogeneously broadened. The strong dependence of the spectra on the probe-beam polarization indicates the existence of large optical anisotropy of the cold-atom sample, which is attributed to the recoil effects. We point out that the recoil-induced resonances can be isolated from other contributions, making pump-probe spectroscopy a highly sensitive diagnostic tool for atoms in a working MOT.

physics.atom-ph↗