Showing papers on "Dipole published in 2022"

Dipolar physics: a review of experiments with magnetic quantum gases

Abstract: Since the achievement of quantum degeneracy in gases of chromium atoms in 2004, the experimental investigation of ultracold gases made of highly magnetic atoms has blossomed. The field has yielded the observation of many unprecedented phenomena, in particular those in which long-range and anisotropic dipole–dipole interactions (DDIs) play a crucial role. In this review, we aim to present the aspects of the magnetic quantum-gas platform that make it unique for exploring ultracold and quantum physics as well as to give a thorough overview of experimental achievements. Highly magnetic atoms distinguish themselves by the fact that their electronic ground-state configuration possesses a large electronic total angular momentum. This results in a large magnetic moment and a rich electronic transition spectrum. Such transitions are useful for cooling, trapping, and manipulating these atoms. The complex atomic structure and large dipolar moments of these atoms also lead to a dense spectrum of resonances in their two-body scattering behaviour. These resonances can be used to control the interatomic interactions and, in particular, the relative importance of contact over dipolar interactions. These features provide exquisite control knobs for exploring the few- and many-body physics of dipolar quantum gases. The study of dipolar effects in magnetic quantum gases has covered various few-body phenomena that are based on elastic and inelastic anisotropic scattering. Various many-body effects have also been demonstrated. These affect both the shape, stability, dynamics, and excitations of fully polarised repulsive Bose or Fermi gases. Beyond the mean-field instability, strong dipolar interactions competing with slightly weaker contact interactions between magnetic bosons yield new quantum-stabilised states, among which are self-bound droplets, droplet assemblies, and supersolids. Dipolar interactions also deeply affect the physics of atomic gases with an internal degree of freedom as these interactions intrinsically couple spin and atomic motion. Finally, long-range dipolar interactions can stabilise strongly correlated excited states of 1D gases and also impact the physics of lattice-confined systems, both at the spin-polarised level (Hubbard models with off-site interactions) and at the spinful level (XYZ models). In the present manuscript, we aim to provide an extensive overview of the various related experimental achievements up to the present.

Strong Nonlinearity Induced by Coaxial Alignment of Polar Chain and Dense [BO3] Units in CaZn2(BO3)2.

Abstract: Discovery of new efficient nonlinear optical (NLO) materials with large second-order nonlinearity for short-wave UV spectral region (λ PM ≤ 266 nm, PM = phase-matching) is still very challenging. Herein, by applying tetrahedra substitution strategy based on Sr 2 Be 2 B 2 O 7 (SBBO), a new beryllium-free borate CaZn 2 (BO 3 ) 2 with double-layered configuration was rationally designed, which not only preserves the structural merits but also eliminates the limitations of SBBO crystal. CaZn 2 (BO 3 ) 2 shows a large PM second harmonic generation (SHG) reponse of 3.8×KDP, which is 38 times higher than its barium analogue. This enhancement originates from the 1 [Zn 2 O 6 ] ∞ polar chains with large net dipole moment and [BO 3 ] units with high NLO active density. Our findings show the great significance of [ZnO 4 ] tetrahedra introduced strategy to design beryllium-free SBBO-type NLO crystals and also verify the feasibility of using simple non-isomorphic substitution to induce giant second-order nonlinearity enhancement.

Process‐Aid Solid Engineering Triggers Delicately Modulation of Y‐Series Non‐Fullerene Acceptor for Efficient Organic Solar Cells

Abstract: Volatile solids with symmetric π‐backbone are intensively implemented on manipulating the nanomorphology for improving the operability and stability of organic solar cells. However, due to the isotropic stacking, the announced solids with symmetric geometry cannot modify the microscopic phase separation and component distribution collaboratively, which will constrain the promotion of exciton splitting and charge collection efficiency. Inspired by the superiorities of asymmetric configuration, a novel process‐aid solid (PAS) engineering is proposed. By coupling with BTP core unit in Y‐series molecule, an asymmetric, volatile 1,3‐dibromo‐5‐chlorobenzene solid can induce the anisotropic dipole direction, elevated dipole moment, and interlaminar interaction spontaneously. Due to the synergetic effects on the favorable phase separation and desired component distribution, the PAS‐treated devices feature the evident improvement of exciton splitting, charge transport, and collection, accompanied by the suppressed trap‐assisted recombination. Consequently, an impressive fill factor of 80.2% with maximum power conversion efficiency (PCE) of 18.5% in the PAS‐treated device is achieved. More strikingly, the PAS‐treated devices demonstrate a promising thickness‐tolerance character, where a record PCE of 17.0% is yielded in PAS devices with a 300 nm thickness photoactive layer, which represents the highest PCE for thick‐film organic solar cells.

Dark matter from axion strings with adaptive mesh refinement

Abstract: Axions are hypothetical particles that may explain the observed dark matter density and the non-observation of a neutron electric dipole moment. An increasing number of axion laboratory searches are underway worldwide, but these efforts are made difficult by the fact that the axion mass is largely unconstrained. If the axion is generated after inflation there is a unique mass that gives rise to the observed dark matter abundance; due to nonlinearities and topological defects known as strings, computing this mass accurately has been a challenge for four decades. Recent works, making use of large static lattice simulations, have led to largely disparate predictions for the axion mass, spanning the range from 25 microelectronvolts to over 500 microelectronvolts. In this work we show that adaptive mesh refinement simulations are better suited for axion cosmology than the previously-used static lattice simulations because only the string cores require high spatial resolution. Using dedicated adaptive mesh refinement simulations we obtain an over three order of magnitude leap in dynamic range and provide evidence that axion strings radiate their energy with a scale-invariant spectrum, to within ~5% precision, leading to a mass prediction in the range (40,180) microelectronvolts.

Tunable light-induced dipole-dipole interaction between optically levitated nanoparticles

Abstract: Arrays of optically trapped nanoparticles have emerged as a platform for the study of complex nonequilibrium phenomena. Analogous to atomic many-body systems, one of the crucial ingredients is the ability to precisely control the interactions between particles. However, the optical interactions studied thus far only provide conservative optical binding forces of limited tunability. In this work, we exploit the phase coherence between the optical fields that drive the light-induced dipole-dipole interaction to couple two nanoparticles. In addition, we effectively switch off the optical interaction and observe electrostatic coupling between charged particles. Our results provide a route to developing fully programmable many-body systems of interacting nanoparticles with tunable nonreciprocal interactions, which are instrumental for exploring entanglement and topological phases in arrays of levitated nanoparticles. Description Levitated interactions The ability to trap macroscopic objects in vacuum, levitating them with optical fields and cooling them to their motional ground state provides access to highly sensitive sensors for applications in metrology. Rieser et al. demonstrate the trapping of two silica nanoparticles and explore the light-induced dipole-dipole interactions between them (see the Perspective by Pedernales). The results provide a route to developing a fully tunable and scalable platform to study entanglement and topological quantum matter with nanoscale objects. —ISO Optical trapping was used to explore the light-induced interactions between two silica nanoparticles.

Plasmonically induced transparency in phase-coupled graphene nanoribbons

Abstract: Due to its transparent and highly dispersive nature, plasmonically induced transparency (PIT) has become an attractive field in the on-chip control of light. Conventional methods to achieve PIT are only limited to the lowest dipole-dipole or dipole-combined quadrupole modes by breaking structural symmetry. Consequently, a general methodological framework for accurately designing all-order PIT remains absent. In this paper, we propose a theoretical scheme to achieve unidirectional odd-to-even order PIT by establishing a model with two layers of periodic graphene nanoribbons. The underlying physical principles are uncovered by defining the additional resonant phase of one mode over the other as phase difference, which predicts that the PIT effects appear (disappear) generally near the positions where the phase difference is around odd (even) multiple numbers of \ensuremath{\pi}. Full-wave simulations and theoretical analysis are used to demonstrate our proposal, revealing that the proposed PIT concept possesses good robustness against both the ribbon width and the relative ribbon positions. Our results serve to provide an effective method to realize all-order PIT and to design PIT-based photonic devices.

Dipolar excitonic insulator in a moiré lattice

Abstract: Two-dimensional moiré materials provide a highly controllable solid-state platform for studies of quantum phenomena1,2,3. To date, experimental studies have focused on correlated electronic states, whereas correlated bosonic states in moiré materials have received less attention. Here we report the observation of a correlated dipolar excitonic insulator—a charge-insulating state driven by exciton formation4—in a device where a WSe2 monolayer and WSe2/WS2 moiré bilayer are coupled via Coulomb interactions. The system is a Mott insulator when all the holes reside in the moiré layer. Under an out-of-plane electric field, the holes can be continuously transferred to the WSe2 monolayer, but remain strongly bound to the empty moiré sites, effectively forming an interlayer exciton fluid in the moiré lattice. We further observe the emergence of local magnetic moments in the WSe2 monolayer induced by the strong interlayer Coulomb correlation. Our result provides a platform for realizing correlated quantum phenomena described by bosonic lattice models in a solid-state system, complementary to cold-atom setups5.

Direct observation of geometric and sliding ferroelectricity in an amphidynamic crystal

Abstract: Sliding ferroelectricity is a recently observed polarity existing in two-dimensional materials. However, due to their weak polarization and poor electrical insulation in these materials, all available experimental evidence till now are indirect, with most based on transport properties in the nanoscale or piezoresponse force microscopy. We report the direct observation of sliding ferroelectricity, using a high-quality amphidynamic single crystal, (15-Crown-5)Cd$_3$Cl$_6$, which possesses a large band-gap and so allows direct measurement of P-E hysteresis. This coordination polymer is a van der Waals material, which is composed of inorganic stators and organic rotators as measured using XRD and NMR characterisation. From DFT calculations, we find that after the freezing of rotators an electric dipole is generated in each layer driven by the geometric mechanism, meanwhile a comparable ferroelectric polarization originates from the interlayer sliding. The net polarization of these two components can be directly measured and manipulated. Our finding provides insight into low-dimensional ferroelectrics, especially the controlling of synchronous dynamics of rotating molecules and sliding layers in solids.

Deferred Polarization Saturation Boosting Superior Energy-Storage Efficiency and Density Simultaneously under Moderate Electric Field in Relaxor Ferroelectrics

Abstract: High-temperature dielectric Bi0.5Na0.5TiO3 (BNT)-based relaxors near a morphotropic phase boundary are developed with excellent energy storage performance. Random distribution of polar nanoregions induced by composition modulation would disrupt the ferroelectric long-range dipolar alignment and weaken the coupling between the ferroelectric domains, yielding slender and deferred polarization–electric field hysteresis loops with relatively high saturation polarization. The reversible nano-domain orientation and growth in relaxors under a delayed electric field result in negligible remnant polarization and advantageous energy storage properties. Simultaneously, superior recoverable energy storage density and efficiency are gained, significantly surpassing the state-of-the-art dielectric energy storage materials under similar moderate electric fields. Vacancies, defect dipole behavior, and structural evolution that relied on an electric field and temperature are discussed to disclose the underlying mechanism associated with phase transition. Even thermal stability and large electrostrictive strain with low hysteresis are achieved in elevated temperatures. These features demonstrate the promising candidates for dielectric energy-storage application and provide a strategy in designing relaxors.

Simultaneously achieving giant piezoelectricity and record coercive field enhancement in relaxor-based ferroelectric crystals

Abstract: A large coercive field (EC) and ultrahigh piezoelectricity are essential for ferroelectrics used in high-drive electromechanical applications. The discovery of relaxor-PbTiO3 crystals is a recent breakthrough; they currently afford the highest piezoelectricity, but usually with a low EC. Such performance deterioration occurs because high piezoelectricity is interlinked with an easy polarization rotation, subsequently favoring a dipole switch under small fields. Therefore, the search for ferroelectrics with both a large EC and ultrahigh piezoelectricity has become an imminent challenge. Herein, ternary Pb(Sc1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 crystals are reported, wherein the dispersed local heterogeneity comprises abundant tetragonal phases, affording a EC of 8.2 kV/cm (greater than that of Pb(Mg1/3Nb2/3)O3-PbTiO3 by a factor of three) and ultrahigh piezoelectricity (d33 = 2630 pC/N; d15 = 490 pC/N). The observed EC enhancement is the largest reported for ultrahigh-piezoelectric materials, providing a simple, practical, and universal route for improving functionalities in ferroelectrics with an atomic-level understanding.

Regulating Optical Activity and Anisotropic Second-Harmonic Generation in Zero-Dimensional Hybrid Copper Halides.

Abstract: Structural engineering permits the introduction of chirality into organic-inorganic hybrid metal halides (HMHs), which creates a promising and exclusive material for applications in various optoelectronics. However, the optical activity regulation of chiral HMHs remains largely unexplored. In this work, we have synthesized two pairs of lead-free chiral HMHs with a zero-dimensional tetrahedral arrangement, i.e., (R- and S-1-(1-naphthyl)ethylammonium)2CuCl4 and (R- and S-1-(2-naphthyl)ethylammonium)2CuCl4. The magnitude of optical activity in these HMHs can be efficiently modulated as a result of the different magnetic transition dipole moments. Furthermore, these HMHs exhibited effective second-harmonic generation (SHG) and distinct SHG-circular dichroism (CD), with (R-1-(1-naphthyl)ethylammonium)2CuCl4 having an anisotropy factor (gSHG-CD) of up to 0.41. This work not only provides insights into regulating the optical activity and anisotropic SHG effect of lead-free chiral HMHs but also confirms the feasibility of SHG-CD spectroscopy as a promising tool for characterizing the intrinsic optical activity of chiral materials.

Multiple-Resonance-Induced Thermally Activated Delay Fluorescence Materials Based on Indolo[3,2,1-jk]carbazole with an Efficient Narrowband Pure-Green Electroluminescence.

Abstract: Herein, we report two multiple-resonance thermally activated delayed fluorescence emitters (VTCzBN and TCz-VTCzBN) based on indolo[3,2,1-jk]carbazole unit and boron-nitrogen skeletons, whose emissions peaking at 496 and 521 nm with full width at half maximum of 34 and 29 nm, respectively. Meanwhile, fast rate constants of reverse intersystem crossing of above 106 s-1 are obtained due to small singlet-triplet energy gaps and large spin-orbital coupling values. Notably, planar molecular structures along the transition dipole moment direction endow them with high horizontal emitting dipole ratios of up to 94%. Consequently, the corresponding organic light-emitting diodes (OLEDs) show the maximum external quantum efficiencies of 31.7% and 32.2%, respectively. Particularly, OLED with TCz-VTCzBN display ultra-pure green emission with Commission Internationale de l´Eclairage coordinates of (0.22, 0.71), consistent with the green display standard of the National Television System Committee.

Enhanced Dielectric and Ferroelectric Properties of Poly(vinylidene fluoride) through Annealing Oriented Crystallites under High Pressure

Abstract: The structural manipulation of the electroactive β phase of poly(vinylidene fluoride) (PVDF) is particularly important in sensor and actuator applications. Herein, an efficient way to enhance dielectric and ferroelectric properties of PVDF films by annealing preoriented PVDF films through thermal treatment combined with the pressure field is proposed. During annealing processing, an appropriate pressure is attributed to the efficient dipole rotation and results in complete phase transformation of the nonpolar α phase (TGTG′) into the polar β phase (TTTT). Moreover, the appropriate pressure and temperature fields synergistically promote a more perfect alignment of the main chain in β-crystallites along the stretching direction. Thus, the pure β phase with ultrahigh orientation (Herman’s orientation factor >0.97) is successfully obtained. Moreover, the enhanced mobility of molecular chains with the increase of temperature contributes to the perfection of β-crystallites with high crystallinity. The relaxation of oriented chains in the amorphous region at high temperature during the annealing process is obviously inhibited by high pressure, leading to increased density of dipoles capable of efficient rotation under an electric field. The unique structure obtained imparts a distinctly enhanced dielectric and ferroelectric properties to the PVDF films. The highest dielectric constant at room temperature is observed in preoriented films annealed at 160 °C due to the optimal chain orientation. Moreover, the film with more perfect and tightly packed β-crystallites annealed at 180 °C shows clearly ferroelectric switching and the maximum remnant polarization (5.8 μC/cm2). The outcomes of this work indicate that a rational combination of pressure and temperature fields could effectively achieve optimal dielectric and ferroelectric properties of PVDF oriented films.

Mapping the energy level alignment at donor/acceptor interfaces in non-fullerene organic solar cells

Abstract: Energy level alignment (ELA) at donor (D) -acceptor (A) heterojunctions is essential for understanding the charge generation and recombination process in organic photovoltaic devices. However, the ELA at the D-A interfaces is largely underdetermined, resulting in debates on the fundamental operating mechanisms of high-efficiency non-fullerene organic solar cells. Here, we systematically investigate ELA and its depth-dependent variation of a range of donor/non-fullerene-acceptor interfaces by fabricating and characterizing D-A quasi bilayers and planar bilayers. In contrast to previous assumptions, we observe significant vacuum level (VL) shifts existing at the D-A interfaces, which are demonstrated to be abrupt, extending over only 1-2 layers at the heterojunctions, and are attributed to interface dipoles induced by D-A electrostatic potential differences. The VL shifts result in reduced interfacial energetic offsets and increased charge transfer (CT) state energies which reconcile the conflicting observations of large energy level offsets inferred from neat films and large CT energies of donor - non-fullerene-acceptor systems.

Room-temperature logic-in-memory operations in single-metallofullerene devices

Abstract: In-memory computing provides an opportunity to meet the growing demands of large data-driven applications such as machine learning, by colocating logic operations and data storage. Despite being regarded as the ultimate solution for high-density integration and low-power manipulation, the use of spin or electric dipole at the single-molecule level to realize in-memory logic functions has yet to be realized at room temperature, due to their random orientation. Here, we demonstrate logic-in-memory operations, based on single electric dipole flipping in a two-terminal single-metallofullerene (Sc2C2@Cs(hept)-C88) device at room temperature. By applying a low voltage of ±0.8 V to the single-metallofullerene junction, we found that the digital information recorded among the different dipole states could be reversibly encoded in situ and stored. As a consequence, 14 types of Boolean logic operation were shown from a single-metallofullerene device. Density functional theory calculations reveal that the non-volatile memory behaviour comes from dipole reorientation of the [Sc2C2] group in the fullerene cage. This proof-of-concept represents a major step towards room-temperature electrically manipulated, low-power, two-terminal in-memory logic devices and a direction for in-memory computing using nanoelectronic devices. Single-molecule electronics provide the potential solution for high-density integration and low-power consumption in massive data-driven applications, but have yet to be explored. Here, the authors report low-power logic-in-memory operations, based on single electric dipole flipping in the two-terminal single-metallofullerene device at room temperature.

Anisotropic nanocrystal superlattices overcoming intrinsic light outcoupling efficiency limit in perovskite quantum dot light-emitting diodes

Abstract: Quantum dot (QD) light-emitting diodes (LEDs) are emerging as one of the most promising candidates for next-generation displays. However, their intrinsic light outcoupling efficiency remains considerably lower than the organic counterpart, because it is not yet possible to control the transition-dipole-moment (TDM) orientation in QD solids at device level. Here, using the colloidal lead halide perovskite anisotropic nanocrystals (ANCs) as a model system, we report a directed self-assembly approach to form the anisotropic nanocrystal superlattices (ANSLs). Emission polarization in individual ANCs rescales the radiation from horizontal and vertical transition dipoles, effectively resulting in preferentially horizontal TDM orientation. Based on the emissive thin films comprised of ANSLs, we demonstrate an enhanced ratio of horizontal dipole up to 0.75, enhancing the theoretical light outcoupling efficiency of greater than 30%. Our optimized single-junction QD LEDs showed peak external quantum efficiency of up to 24.96%, comparable to state-of-the-art organic LEDs.

Thermal management of chips by a device prototype using synergistic effects of 3-D heat-conductive network and electrocaloric refrigeration

Abstract: Abstract With speeding up development of 5 G chips, high-efficient thermal structure and precise management of tremendous heat becomes a substantial challenge to the power-hungry electronics. Here, we demonstrate an interpenetrating architecture of electrocaloric polymer with highly thermally conductive pathways that achieves a 240% increase in the electrocaloric performance and a 300% enhancement in the thermal conductivity of the polymer. A scaled-up version of the device prototype for a single heat spot cooling of 5 G chip is fabricated utilizing this electrocaloric composite and electromagnetic actuation. The continuous three-dimensional (3-D) thermal conductive network embedded in the polymer acts as nucleation sites of the ordered dipoles under applied electric field, efficiently collects thermal energy at the hot-spots arising from field-driven dipolar entropy change, and opens up the high-speed conduction path of phonons. The synergy of two components, thus, tackles the challenge of sluggish heat dissipation of the electroactive polymers and their contact interfaces with low thermal conductivity, and more importantly, significantly reduces the electric energy for switching the dipolar states during the electrocaloric cycles, and increases the manipulable entropy at the low fields. Such a feasible solution is inevitable to the precisely fixed-point thermal management of next-generation smart microelectronic devices.

A two-directional vibrational probe reveals different electric field orientations in solution and an enzyme active site

Abstract: The catalytic power of an electric field depends on its magnitude and orientation with respect to the reactive chemical species. Understanding and designing new catalysts for electrostatic catalysis thus requires methods to measure the electric field orientation and magnitude at the molecular scale. We demonstrate that electric field orientations can be extracted using a two-directional vibrational probe by exploiting the vibrational Stark effect of both the C=O and C–D stretches of a deuterated aldehyde. Combining spectroscopy with molecular dynamics and electronic structure partitioning methods, we demonstrate that, despite distinct polarities, solvents act similarly in their preference for electrostatically stabilizing large bond dipoles at the expense of destabilizing small ones. In contrast, we find that for an active-site aldehyde inhibitor of liver alcohol dehydrogenase, the electric field orientation deviates markedly from that found in solvents, which provides direct evidence for the fundamental difference between the electrostatic environment of solvents and that of a preorganized enzyme active site. Preorganized electric fields may be essential for the extraordinary catalytic power of enzymes. Now, it has been demonstrated how electric field strengths can be monitored along two directions using a vibrational Stark probe, enabling the observation of distinct electric field orientations in an enzyme active site compared with those in simple solvents.

All-optical reconstruction of three-band transition dipole moments by the crystal harmonic spectrum from a two-color laser pulse.

Abstract: When a bulk solid is irradiated by an intense laser pulse, transition dipole moments (TDMs) between different energy bands have an important influence on the ultra-fast dynamic process. In this paper, we propose a new all-optical method to reconstruct the k-dependent TDMs between multi-bands using a crystal high-order harmonic generation (HHG). Taking advantage of an obvious separation of bandgaps between three energy bands of an MgO crystal along the <001 > direction, a continuous harmonic spectrum with two plateaus can be generated by a two-color laser pulse. Furthermore, the first harmonic platform is mainly dominated by the polarization between the first conduction band and the valence band, and the second one is largely attributed to the interband HHG from the second conduction band and the valence band. Therefore, the harmonic spectrum from a single quantum trajectory can be adopted to map TDMs between the first, second conduction bands, and the valence one. Our work is of great significance for understanding the instantaneous properties of solid materials in the strong laser field, and will strongly promote the development of the HHG detection technology.

Bound states in the continuum supported by silicon oligomer metasurfaces.

Abstract: Oligomer metasurfaces have attracted a lot of attention in recent years because of their ability to drive strong resonance effects. In this work, by perturbing the symmetry of the structure, we find that there are a large number of resonance modes in the oligomer metasurfaces associated with the optical bound states in the continuum (BICs) near the communication wavelength. When the positions of two nanodisks of the hexamer oligomers are moved along the x- or y-directions at the same time, the mirror symmetry is broken, and an electric quadrupole BIC and three magnetic dipole BICs are excited. The results of near-field distribution of three-dimensional nanodisks and far-field scattering of multiple dipoles in each quasi-BIC reveal that the four BICs present different optical characteristics. It is noted that the method of symmetry breaking by moving the position of nanodisks can accurately control the asymmetric parameter of symmetry-protected BICs, which provides a route for the realization of ultrahigh quality (Q)-factor oligomer metasurfaces in experiment.

Extended Bose–Hubbard model with dipolar excitons

Abstract: The Hubbard model constitutes one of the most celebrated theoretical frameworks of condensed-matter physics. It describes strongly correlated phases of interacting quantum particles confined in lattice potentials1,2. For bosons, the Hubbard Hamiltonian has been deeply scrutinized for short-range on-site interactions3-6. However, accessing longer-range couplings has remained elusive experimentally7. This marks the frontier towards the extended Bose-Hubbard Hamiltonian, which enables insulating ordered phases at fractional lattice fillings8-12. Here we implement this Hamiltonian by confining semiconductor dipolar excitons in an artificial two-dimensional square lattice. Strong dipolar repulsions between nearest-neighbour lattice sites then stabilize an insulating state at half filling. This characteristic feature of the extended Bose-Hubbard model exhibits the signatures theoretically expected for a chequerboard spatial order. Our work thus highlights that dipolar excitons enable controlled implementations of boson-like arrays with strong off-site interactions, in lattices with programmable geometries and more than 100 sites.