Dc Stark Effect Research Articles

Continuous broadband microwave electric field measurement in Rydberg atoms based on the DC Stark effect

We demonstrate a method for broadband tunable continuous frequency electric field measurement based on the DC Stark effect in Rydberg atoms. In our experiment, we place a pair of parallel electrode plates inside the atomic vapor cell, utilizing the DC Stark effect to induce splitting and shifting of the Rydberg energy levels, thereby altering the resonance frequency of the Stark subpeaks. By employing the 52D5/2 Rydberg state, we achieve electric field measurements in the frequency range of 5.083–14.470 GHz. At an EDC of 3.45 V/cm and a resonant microwave frequency of 14.470 GHz, using heterodyne technology, the microwave electric field sensitivity is 538.89 μV/cm/√Hz, with a linear dynamic range of 23 dB. In comparison, a Rydberg heterodyne receiver with an EDC of 0 V/cm and a resonant microwave frequency of 5.083 GHz has a sensitivity of 5.43 μV/cm/√Hz and a linear dynamic range of 51 dB. This work will promote the study of atomic microwave receivers in continuous microwave frequency measurement.

Polarization-Driven Asymmetric Electronic Response of Monolayer Graphene to Polymer Zwitterions Probed from Both Sides.

We investigated the nature of graphene surface doping by zwitterionic polymers and the implications of weak in-plane and strong through-plane screening using a novel sample geometry that allows direct access to either the graphene or the polymer side of a graphene/polymer interface. Using both Kelvin probe and electrostatic force microscopies, we observed a significant upshift in the Fermi level in graphene of ∼260 meV that was dominated by a change in polarizability rather than pure charge transfer with the organic overlayer. This physical picture is supported by density functional theory (DFT) calculations, which describe a redistribution of charge in graphene in response to the dipoles of the adsorbed zwitterionic moieties, analogous to a local DC Stark effect. Strong metallic-like screening of the adsorbed dipoles was observed by employing an inverted geometry, an effect identified by DFT to arise from a strongly asymmetric redistribution of charge confined to the side of graphene proximal to the zwitterion dipoles. Transport measurements confirm n-type doping with no significant impact on carrier mobility, thus demonstrating a route to desirable electronic properties in devices that combine graphene with lithographically patterned polymers.

Photon-mediated entanglement scheme between a ZnO semiconductor defect and a trapped Yb ion

We propose an optical scheme to generate an entangled state between a trapped ion and a solid state donor qubit through which-path erasure of identical photons emitted from the two systems. The proposed scheme leverages the similar transition frequencies between In donor bound excitons in ZnO and the P21/2 to S21/2 transition in Yb+. The lifetime of the relevant ionic state is longer than that of the ZnO system by a factor of 6, leading to a mismatch in the temporal profiles of emitted photons. A detuned cavity-assisted Raman scheme weakly excites the donor with a shaped laser pulse to generate photons with a 0.99 temporal overlap to the Yb+ emission and partially shift the emission of the defect toward the Yb+ transition. The remaining photon shift is accomplished via the dc Stark effect. We show that an entanglement rate of 2.1×104 s−1 and an entanglement fidelity of 94% can be attained using a weak excitation scheme with reasonable parameters.

СПЕКТРОСКОПІЯ БАГАТОЕЛЕКТРОННОГО АТОМА В DC ЕЛЕКТРИЧНОМУ ПОЛІ: МОДИФІКОВАНИЙ МЕТОД ОПЕРАТОРНОЇ ТЕОРІЇ ЗБУРЕНЬ ДЛЯ ОПИСУ ШТАРКIВСЬКИХ РЕЗОНАНСІВ

It is presented a new modified method to calculation of the Stark resonances energies characteristics (energies and widths) for the multielectron atomic systems in a DC electric field. The method is based on the modified operator perturbation theory. The latter allows an accurate, consistent treatment of a strong field DC Stark effect and includes the physically reasonable distorted-waves approximation in the frame of the formally exact quantum-mechanical procedure. As illustration, some test data for the Stark resonances energies and widths in the lithium atom spectrum are presented and compared with results of calculations within the alternative consistent sophisticated methods

OPTIMIZED RELATIVISTIC OPERATOR PERTURBATION THEORY IN SPECTROSCOPY OF MULTIELECTRON ATOM IN A DC ELECTRIC FIELD: SENSING SPECTRAL PARAMETERS

It is developed the optimized version of relativistic operator perturbation theory approach to calculation of the Stark resonances energies characteristics (energies and widths) for the multielectron atomic systems in an electromagnetic field. A new approach allows to perform an accurate, consistent treatment of a strong field DC(AC) Stark effect and includes the physically reasonable distorted-waves approximation in the frame of the formally exact relativistic quantum-mechanical procedure. As illustration, some test data for the Stark resonances energies and widths in the heavy multielectron atoms (caesium, francium) are presented and compared with results of calculations within the alternative consistent sophisticated methods etc.

Stark tuning and electrical charge state control of single divacancies in silicon carbide

Neutrally charged divacancies in silicon carbide (SiC) are paramagnetic color centers whose long coherence times and near-telecom operating wavelengths make them promising for scalable quantum communication technologies compatible with existing fiber optic networks. However, local strain inhomogeneity can randomly perturb their optical transition frequencies, which degrades the indistinguishability of photons emitted from separate defects and hinders their coupling to optical cavities. Here, we show that electric fields can be used to tune the optical transition frequencies of single neutral divacancy defects in 4H-SiC over a range of several GHz via the DC Stark effect. The same technique can also control the charge state of the defect on microsecond timescales, which we use to stabilize unstable or non-neutral divacancies into their neutral charge state. Using fluorescence-based charge state detection, we show that both 975 nm and 1130 nm excitation can prepare their neutral charge state with near unity efficiency.

DC Stark addressing for quantum memory in Tm:YAG

We observed a linear DC Stark effect for 3 H 6 – 3 H 4 optical transition of Tm 3+ ions in Y 3 Al 5 O 12 . We observed that application of electric field pulse suppresses the two-pulse photon echo signal. If we then apply a second electric pulse of opposite polarity the echo signal is restored again, which indicates the linear nature of the observed effect. The effect is present despite the D 2 symmetry of the Tm 3+ sites that prohibits a linear Stark effect. Experimental data analysis shows that the observed electric field influence can be attributed to defects that break the local crystal field symmetry near Tm 3+ ions. Using this effect we demonstrate selective retrieval of light pulses in two-pulse photon echo.

ADVANCED LASER PHOTOIONIZATION SEPARATION SCHEME AND TECHNOLOGY FOR HEAVY RADIOACTIVE ISOTOPES AND NUCLEAR ISOMERS

We present new optimal scheme of the separating highly radioactive isotopes and products of atomics energetics such as 210-214Fr, 133,135,137Cs and others, which is based on the selective laser excitation of the isotopes atoms into excited Rydberg states and further autoionization or DC electric field pulse ionization. As result, requirements to energetic of the ionized pulse are decreased at several orders. And an effectiveness of a scheme increases. There are theoretically calculated values of the characteristics of heavy Rydberg atoms in an external electromagnetic field (DC Stark effect) In particular, data on the energy level, the energy widths of Stark resonances for Rydberg Cs, Fr (n <50).

Experimental study of the (4)0− short-range electronic state of the 85Rb133Cs molecule by high resolution photoassociation spectroscopy

We present the formation of ultracold 85Rb133Cs molecules in the (4)0− short-range electronic state and the measurement of the permanent electric dipole moment by high resolution photoassociation spectroscopy. With the rotationally resolved photoassociation spectra via resonance-enhanced two-photon ionization, spectral data have been extended to more vibrational levels compared to previous observations. Precise electric dipole moments are obtained by using the DC Stark effect of the photoassociation spectrum. These studies containing previously unobserved electronic states are important to understand the molecular structure and discover transition pathways for transferring ultracold atoms to deeply bound rovibrational levels of the electronic ground state.

Stark Effect Spectroscopy of Mono- and Few-Layer MoS2.

We demonstrate electrical control of the A-exciton interband transition in mono- and few-layer MoS2 crystals embedded into photocapacitor devices via the DC Stark effect. Electric field-dependent low-temperature photoluminescence spectroscopy reveals a significant tuneability of the A-exciton transition energy up to ∼ 16 meV from which we extract the mean DC exciton polarizability ⟨β̅N⟩ = (0.58 ± 0.25) × 10(-8) Dm V(-1). The exciton polarizability is shown to be layer-independent, indicating a strong localization of both electron and hole wave functions in each individual layer.

Static and dynamic polarizability and the Stark and blackbody-radiation frequency shifts of the molecular hydrogen ionsH2+,HD+, andD2+

We calculate the DC Stark effect for three molecular hydrogen ions in the non-relativistic approximation. The effect is calculated both in dependence on the rovibrational state and in dependence on the hyperfine state. We discuss special cases and approximations. We also calculate the AC polarisabilities for several rovibrational levels, and therefrom evaluate accurately the black-body radiation shift, including the effects of excited electronic states. The results enable the detailed evaluation of certain systematic shifts of the transitions frequencies for the purpose of ultra-high-precision optical, microwave or radio-frequency spectroscopy in ion traps.

The linear and nonlinear optical properties of trigonal zigzag graphene nanoflakes

Using the Hartree–Fock Su–Sheriffer–Heeger model and the sum-over-state method the linear and nonlinear polarizabilities, the dc Stark effect and the degenerate two-photon absorption (TPA) cross sections of the small-size trigonal zigzag graphene nanoflakes (TZGNs) have been investigated. The obtained dispersion spectra of the second- and third-order polarizabilities and the degenerate TPA cross sections of size-2 and size-3 TZGNs, which, respectively, have 22 carbon atoms with two edge states and 33 carbon atoms with three edge states, show peak values of the order of 10−28 esu, 10−32 esu and 103 GM, respectively. Furthermore, even-size TZGNs show electrostatic induced transparency due to their sizable dc Stark effect, which makes them suitable for linear and nonlinear optoelectronic devices.

Ar I and Ne I spectral line shapes for an abnormal glow discharge diagnostics

We report the results of an Ar I and Ne I line shape study in an abnormal glow discharge operating in argon and neon. The spectral lines were observed along the axis of a cylindrical glow discharge parallel (side-on) and perpendicular (end-on) to the cathode surface. The side-on spectra show spectral line shifting and sometimes simultaneous shifting and splitting in the cathode fall region of the glow discharge. The results of the measured line shift with available data for the dc Stark effect are used for measurement of electric field strength in the cathode fall region of the glow discharge. Electron temperatures of 2860 K and 4770 K in the negative glow region of argon and neon discharges, respectively, were determined from the relative intensities of Ar I or Ne I lines using the Boltzmann plot technique. An electron number density of ≈1020 m−3 (±25%) in the negative glow region of the argon discharge was determined from the widths of two plasma-broadened Ar I lines using theoretical Stark broadening data. The end-on recorded line profiles show 10–40% larger half-widths than the side-on recorded line profiles from the negative glow. This effect is a result of the superposition of line emission in the cathode fall region under the influence of the dc Stark effect on the line profile from the negative glow.

Cathode sheath and hydrogen Balmer lines modelling in a micro-hollow gas discharge

We present a model of the cathode sheath (CS) processes responsible for the broadening of the hydrogen Balmer beta line recorded from a micro-hollow gas discharge (MHGD) and used for simultaneous diagnostics of plasma and CS parameters. The MHGD was generated in a microhole (diameter 100 μm at narrow side and 130 μm at wider side) of a gold-alumina-gold sandwich in the pressure ranges: (100–900) mbar in argon with traces of hydrogen, and (100–400) mbar in pure hydrogen. The electron number density is determined from the plasma broadened line width of the central part of Balmer beta profile, while the average value of electric field strength in the CS and the CS thickness are determined from the extended line wings induced by the dc Stark effect.

Two-Photon Quantum Interference from Separate Nitrogen Vacancy Centers in Diamond

We report on the observation of quantum interference of the emission from two separate nitrogen vacancy (NV) centers in diamond. Taking advantage of optically induced spin polarization in combination with polarization filtering, we isolate a single transition within the zero-phonon line of the nonresonantly excited NV centers. The time-resolved two-photon interference contrast of this filtered emission reaches 66%. Furthermore, we observe quantum interference from dissimilar NV centers tuned into resonance through the dc Stark effect. These results pave the way towards measurement-based entanglement between remote NV centers and the realization of quantum networks with solid-state spins.

Electrical Tuning of Single Nitrogen-Vacancy Center Optical Transitions Enhanced by Photoinduced Fields

We demonstrate precise control over the zero-phonon optical transition energies of individual nitrogen-vacancy (NV) centers in diamond by applying multiaxis electric fields, via the dc Stark effect. The Stark shifts display surprising asymmetries that we attribute to an enhancement and rectification of the local electric field by photoionized charge traps in the diamond. Using this effect, we tune the excited-state orbitals of strained NV centers to degeneracy and vary the resulting degenerate optical transition frequency by >10 GHz, a scale comparable to the inhomogeneous frequency distribution. This technique will facilitate the integration of NV-center spins within photonic networks.

A contribution to spectroscopic diagnostics and cathode sheath modeling of micro-hollow gas discharge in argon

In this paper, the hydrogen Balmer beta line shape from a micro-hollow gas discharge (MHGD) in argon with traces of hydrogen is used for simultaneous diagnostics of plasma and cathode sheath (CS) parameters. For this purpose, a simple model of relevant processes responsible for the line broadening is introduced and applied to the Balmer beta profile recorded from a MHGD generated in the microhole (diameter 100 μm at narrow side and 130 μm at wider side) of a gold-alumina-gold sandwich in the pressure range (100–900 mbar). The electron number density Ne in the range (0.4–4.5) × 1020 m–3 is determined from the width of the central part of the Balmer beta line profile, while, from the extended wings of the Balmer beta profile, induced by dc Stark effect, the next three parameters are determined: the average value Ea of electric field strength in the CS in the range (16–95 kV/cm), the electric field strength E0 at the cathode surface in the range (32–190 kV/cm), and the CS thickness zg in the range (18–70 μm). All four MHGD parameters, Ne, Ea, E0, and zg, compare reasonably well with results of the modeling experiment by M. J. Kushner [J. Phys. D: Appl. Phys. 38, 1633 (2005)]. The results for Ne are compared with other emission experiments.

Decoherence and dephasing errors caused by the dc Stark effect in rapid ion transport

We investigate the error due to D.C. Stark effect for quantum information processing for trapped ion quantum computers using the scalable architecture proposed in J. Res. Natl. Inst. Stan. 103, 259 (1998) and Nature 417, 709 (2002). As the operation speed increases, dephasing and decoherence due to the D.C. Stark effect becomes prominent as a large electric field is applied for transporting ions rapidly. We estimate the relative significance of the decoherence and dephasing effects and find that the latter is dominant. We find that the minimum possible of dephasing is quadratic in the time of flight, and an inverse cubic in the operational time scale. From these relations, we obtain the operational speed-range at which the shifts caused by D.C. Stark effect, no matter follow which trajectory the ion is transported, are no longer negligible. Without phase correction, the maximum speed a qubit can be transferred across a 100 micron-long trap, without excessive error, in about 10 ns for Calcium ion and 50 ps for Beryllium ion. In practice, the accumulated error is difficult to be tracked and calculated, our work gives an estimation to the range of speed limit imposed by D.C. Stark effect.

Manipulation of quantum state transfer in cold Rydberg atom collisions

We investigate the role of the dc Stark effect in multilevel pairwise interactions between cold Rydberg atoms. We have observed the decay of nD+nD quasi-molecules by detecting the products in the (n+2)P state after pulsed excitation for 29⩽n⩽41. The decay rate can be manipulated with a dc electric field and requires a consideration of the multilevel nature of the process to explain the observations. The time dependence of the (n+2)P signal is found to support a time-dependent picture of the dynamics.

Adiabatic potentials for Rydberg atoms in a ponderomotive optical lattice

We calculate the adiabatic potentials and adiabatic wavefunctions of Rydberg atoms in a one-dimensional ponderomotive optical lattice. All lattice-induced couplings between the degenerate high-angular-momentum Rydberg states are taken into account. To obtain insight into the underlying physics, we analyze the numerical results in terms of effective electric and magnetic fields produced by the lattice. Near the inflection points of the lattice potential and for sufficiently low principal quantum numbers (n≲35 in the cases studied), the adiabatic level structure resembles that of the dc Stark effect, and an effective electric-field model can be used to model the lattice-induced perturbation. Near the nodes and anti-nodes of the lattice field, the adiabatic level structure exhibits a combination of adjacent rotational and vibrational energy level sequences. Here, an analogy between the ponderomotive optical lattice and the diamagnetic problem works well to interpret the lattice-induced perturbation in terms of an effective magnetic field.