Z. D. Grujić
A5061611534- Atomic and Subatomic Physics Research
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum optics and atomic interactions
- Quantum, superfluid, helium dynamics
- Dark Matter and Cosmic Phenomena
- Characterization and Applications of Magnetic Nanoparticles
- Advanced MRI Techniques and Applications
- Geomagnetism and Paleomagnetism Studies
- Nuclear Physics and Applications
- Radiation Detection and Scintillator Technologies
- Magnetic Field Sensors Techniques
- Advanced Frequency and Time Standards
- Magneto-Optical Properties and Applications
- Iron oxide chemistry and applications
- Physics of Superconductivity and Magnetism
- Mechanical and Optical Resonators
- Advanced NMR Techniques and Applications
- Computational Fluid Dynamics and Aerodynamics
- Advanced Measurement and Metrology Techniques
- Astronomical Observations and Instrumentation
- Stability and Controllability of Differential Equations
- Quantum and electron transport phenomena
- Particle Detector Development and Performance
- Photonic and Optical Devices
- NMR spectroscopy and applications
Institute of Physics Belgrade
2007-2024
University of Belgrade
2009-2024
University of Fribourg
2013-2023
We present the result of an experiment to measure electric dipole moment (EDM) neutron at Paul Scherrer Institute using Ramsey's method separated oscillating magnetic fields with ultracold neutrons (UCN). Our measurement stands in long history EDM experiments probing physics violating time reversal invariance. The salient features this were use a Hg-199 co-magnetometer and array optically pumped cesium vapor magnetometers cancel correct for field changes. statistical analysis was performed...
We present for the first time a detailed and comprehensive analysis of experimental results that set current world sensitivity limit on magnitude electric dipole moment (EDM) neutron. have extended enhanced our earlier to include recent developments in understanding effects gravity depolarizing ultracold neutrons (UCN); an improved calculation spectrum neutrons; conservative estimates other possible systematic errors, which are also shown be consistent with more measurements undertaken...
We report on a search for ultralow-mass axionlike dark matter by analyzing the ratio of spin-precession frequencies stored ultracold neutrons and 199Hg atoms an axion-induced oscillating electric dipole moment neutron axion-wind effect. No signal consistent with is observed axion mass range 10−24≤ma≤10−17 eV. Our null result sets first laboratory constraints coupling to gluons, which improve astrophysical limits up 3 orders magnitude, also improves previous nucleons factor 40.Received 29...
Abstract Ultralight bosons such as axion-like particles are viable candidates for dark matter. They can form stable, macroscopic field configurations in the of topological defects that could concentrate matter density into many distinct, compact spatial regions small compared with Galaxy but much larger than Earth. Here we report results search transient signals from domain walls by using global network optical magnetometers exotic (GNOME) physics searches. We data, consisting correlated...
In recent years diode laser sources have become widespread and reliable tools in magneto-optical spectroscopy. particular, laser-driven atomic magnetometers found a wide range of practical applications. More recently, so-called magnetically silent variants been developed. While conventional the magnetic resonance transitions between sublevels are phase-coherently driven by weak oscillating field, use schemes which either frequency (FM) or amplitude (AM) light beam is modulated. Here we...
It has been proposed that there could be a mirror copy of the standard model particles, restoring parity symmetry in weak interaction on global level. Oscillations between neutral particle, such as neutron, and its counterpart potentially answer various standing issues physics today. Astrophysical studies terrestrial experiments led by ultracold neutron storage measurements have investigated to mirror-neutron oscillations imposed constraints theoretical parameters. Recently, further analysis...
We present the design of a next-generation experiment, n2EDM, currently under construction at ultracold neutron source Paul Scherrer Institute (PSI) with aim carrying out high-precision search for an electric dipole moment neutron. The project builds on experience gained previous apparatus operated PSI until 2017, and is expected to deliver order magnitude better sensitivity provision further substantial improvements. An overview experimental method setup given, requirements are derived, its...
Abstract High-precision searches for an electric dipole moment of the neutron (nEDM) require stable and uniform magnetic field environments. We present recent achievements degaussing equilibrating magnetically shielded room (MSR) n2EDM experiment at Paul Scherrer Institute. final configuration that will be used after numerous studies. The optimized procedure results in a residual has been reduced by factor two. ultra-low is achieved with full magnetic-field-coil system, large vacuum vessel...
We present a magnetometer based on optically pumped Cs atoms that measures the magnitude and direction of 1 μT magnetic field. Multiple circularly polarized laser beams were used to probe free spin precession atoms. The design was optimized for long-time stability achieves scalar resolution better than 300 fT integration times ranging from 80 ms 1000 s. best less reached with 1.6 6 able measure field 10 μrad s up 2000
The neutron gyromagnetic ratio has been measured relative to that of the 199Hg atom with an uncertainty 0.8 ppm. We employed apparatus where ultracold neutrons and mercury atoms are stored in same volume report result γn/γHg=3.8424574(30).
We report a new limit on possible short range spin-dependent interaction from the precise measurement of ratio Larmor precession frequencies stored ultracold neutrons and $^{199}$Hg atoms confined in same volume. The was performed $\sim$1$\mu$ T vertical magnetic holding field with apparatus searching for permanent electric dipole moment neutron at Paul Scherrer Institute. A coupling between freely precessing polarized spins unpolarized nucleons wall material can be investigated by tiny...
We present the magnetically shielded room (MSR) for n2EDM experiment at Paul Scherrer Institute which features an interior cubic volume with each side of length 2.92m, thus providing accessible space 25m3. The MSR has 87 openings up to 220mm diameter operate experimental apparatus inside, and intermediate between layers sensitive signal processing electronics. characterization measurements show a remanent magnetic field in central 1m3 below 100pT, 600pT entire inner volume, 4\,cm walls....
The Surrounding Field Compensation (SFC) system described in this work is installed around the four-layer Mu-metal magnetic shield of neutron electric dipole moment spectrometer located at Paul Scherrer Institute. SFC reduces DC component external field by a factor about 20. Within control volume approximately 2.5 m × 3 m, disturbances are attenuated factors 5–50 bandwidth from 10−3 Hz up to 0.5 Hz, which corresponds integration times longer than several hundreds seconds and represent...
The Global Network of Optical Magnetometers to search for Exotic physics (GNOME) is a network geographically separated, time-synchronized, optically pumped atomic magnetometers that being used correlated transient signals heralding exotic physics. GNOME sensitive nuclear- and electron-spin couplings fields from astrophysical sources such as compact dark-matter objects (for example, axion stars domain walls). Properties the sensors sensitivity, bandwidth, noise characteristics are studied in...
We have performed quantitative measurements of the variation on-resonance absorption coefficients ${\ensuremath{\kappa}}_{0}$ four hyperfine components Cs ${D}_{1}$ transition as a function laser power $P$, for pumping with linearly and circularly polarized light. Sublevel populations derived from rate equations assuming isotropic population relaxation (at ${\ensuremath{\gamma}}_{1}$) yield algebraic ${\ensuremath{\kappa}}_{0}(P)$ dependences that do not reproduce experimental findings vapor...
We describe a spin-echo method for ultracold neutrons (UCNs) confined in precession chamber and exposed to $|B_0|=1~\text{\mu T}$ magnetic field. have demonstrated that the analysis of UCN resonance signals combination with knowledge ambient field provides an excellent by which reconstruct energy spectrum ensemble neutrons. The takes advantage relative dephasing spins arising from gravitationally induced striation stored different energies, also permits improved determination vertical...
We describe our approach to atomic magnetometry based on the push-pull optical pumping technique. Cesium vapor is pumped and probed by a resonant laser beam whose circular polarization modulated synchronously with spin evolution dynamics induced static magnetic field. The magnetometer operated in phase-locked loop, it has an intrinsic sensitivity below 20fT/Hz, using room temperature paraffin-coated cell. use monitor field fluctuations of 300fT/Hz.
We compare the expected effects of so-called gravitationally enhanced depolarization ultracold neutrons to measurements carried out in a spin-precession chamber exposed variety vertical magnetic-field gradients. In particular, we have investigated dependence upon these field gradients spin-depolarization rates and also shifts measured neutron Larmor precession frequency. find excellent qualitative agreement, with accounting for several previously unexplained features data.Received 22 June...