About

Danna Freedman is the Frederick George Keyes Professor of Chemistry at MIT. Her research applies the atomistic control inherent to synthetic chemistry to address fundamental questions in physics. Her group focuses on creating the next generation of materials for quantum information science, including molecular materials for applications within quantum computation, sensing, precision metrology, and communication. She works on bottom-up design of molecular-based qubit systems, conferring Ångstrom scale spatial control and chemical specificity for targeted qubit interactions, with the goal of generating qubits with long lifetimes and well-controlled interactions. In addition, her research harnesses geophysically relevant pressures to synthesize previously inaccessible compounds with unusual properties. Using diamond anvil cells as tiny transparent reactors, her group explores new intermetallic compounds and solid-state bonding, creating materials such as the first iron-bismuth binary compound, FeBi2. Her work combines synthetic approaches with phase stability calculations to predict and realize new phases at high pressure, contributing to the discovery of novel materials and phenomena.

Research topics

• Computer Science
• Physics
• Chemistry
• Materials science
• Nanotechnology
• Quantum mechanics
• Condensed matter physics
• Chemical physics
• Organic chemistry
• Artificial Intelligence
• Computational chemistry
• Atomic physics
• Crystallography
• Mineralogy
• Programming language
• Data science
• Nuclear magnetic resonance
• Thermodynamics

Selected publications

• K5Ir: Reduced Iridium Stabilized in a High-Pressure Semimetal

  ChemRxiv · 2026-01-15

  articleOpen accessSenior author

  Alkali binary compounds offer a way to expand our understanding of the periodic table. Specifically, the redox inert nature of these cations, even within some intermetallic compounds, enables one to access exotic oxidation states. Prior work on semiconducting alkali aurides(I-) and platinides(II-) containing transition metal anions stimulated theoretical predictions of the monatomic iridide(III-) anion by reduction of iridium with alkali metals under pressure. We tested these predictions by reacting a K-rich mixture of K and Ir at 19.5(6) GPa and 493 K. This reaction yields K5Ir, which adopts the rare but simple BaSn5 crystal structure. Hybrid functional electronic structure calculations, net atomic charge analysis, and Ir L3-edge X-ray absorption spectroscopy reveal K5Ir is a semimetal with a carrier density ~10^20 cm^−3 which features anionic Ir and both cationic and neutral K on different sites. While the net atomic charge of Ir in K5Ir falls short of that in hypothetical, semiconducting K3Ir, it exceeds those of Pt(II-) in Cs2Pt and Ir(III-) in [Ir(CO)3]^3−, suggesting an extreme for the distribution of charge in the vicinity of a transition metal. First-principles crystal structure prediction corroborates the thermodynamic stability of K5Ir under the preparatory conditions and indicates that several other K−Ir compounds await discovery.

  PublisherOA PDFDOI

• Predicted Ferromagnetism in Discovered Co–Bi Binary Phases

  Journal of the American Chemical Society · 2025-11-17

  articleSenior authorCorresponding

  Binary solid-state materials offer unique insight into how the interplay of factors such as stoichiometry and bonding interactions affects magnetism and electronic properties. We considered systems where a transition metal provides the spin moment and a heavy main group element bolsters strong spin–orbit coupling. Within this context, cobalt, a known component of permanent magnets, and bismuth, functionally the heaviest element stable to radioactive decay, form a compelling combination. The Co–Bi system has been previously shown to exhibit superconductivity in a phase recovered from high pressure. We expected the Co−Bi system could also be ferromagnetic, resulting in two sets of compounds within one chemical system, one superconducting and one ferromagnetic. Subsequently, we investigated the Co–Bi system through both experimental and theoretical approaches to discover new candidates for permanent magnets. Ab initio random structure searching calculations identified five new compounds with diverse structural motifs that may form at higher pressures than previously reported. Experimental high-pressure synthesis yielded four compounds: α-CoBi, α-CoBi2, β-CoBi, and β-CoBi2. Three of these phases, α-CoBi2, β-CoBi, and β-CoBi2, were consistent with the calculated structures, corresponding to a 60% success rate for our structure search and underscoring the strength of combining computation with experiment. Theory predicts β-CoBi and β-CoBi2 are ferromagnetic, with β-CoBi possessing larger magnetocrystalline anisotropy energy than familiar permanent magnets such as CoPt and Nd–Fe–B. These results suggest the Co–Bi system could be a platform for understanding the factors that underpin magnetism and, to an extent, superconductivity in a chemically simple binary system.

  PublisherDOI

• MnBi₂ Is a Permanent Magnet

  Journal of the American Chemical Society · 2025-07-15 · 2 citations

  articleSenior authorCorresponding

  Creating and understanding new permanent magnets requires an understanding of the impact of orbital angular momentum on coercivity. A simple approach to interrogating this relationship is by incorporating high Z (where Z is the atomic number) elements into binary compounds to maximize spin–orbit coupling. The Mn–Bi system is an appealing platform for these studies since it contains MnBi, a permanent magnet with a large coercive field. We previously identified a new compound in the Mn–Bi system, MnBi2, but could not elucidate its magnetic properties ex situ due to its decomposition upon decompression. Here, we harnessed synchrotron X-ray magnetic circular dichroism to probe the magnetism of MnBi2 at high pressure within a diamond anvil cell. Our results indicate that MnBi2 exhibits ferromagnetic hysteresis at both 10 K and room temperature. Through calculations and experiments, we show that orbital angular momentum and spin–orbit coupling from Bi impart magnetic anisotropy in MnBi2. Comparing the Mn–Bi family of compounds, we consider the Bi p and d orbitals to explain the differences in magnetic behavior within the system. Collectively, these results validate leveraging high-Z elements in the synthesis of new hard permanent magnets.

  PublisherDOI

• Symmetry-mediated quantum coherence of W5+ spins in an oxygen-deficient double perovskite

  npj Quantum Materials · 2025-06-18

  articleOpen access

  Elucidating the factors limiting quantum coherence in real materials is essential to the development of quantum technologies. Here we report a strategic approach to determine the effect of lattice dynamics on spin coherence lifetimes using oxygen deficient double perovskites as host materials. In addition to obtaining millisecond T1 spin-lattice lifetimes at T ~ 10 K, measurable quantum superpositions were observed up to room temperature. We determine that T2 enhancement in Sr2CaWO6-δ over previously studied Ba2CaWO6-δ is caused by a dynamically-driven increase in effective site symmetry around the dominant paramagnetic site, assigned as W5+ via electron paramagnetic resonance spectroscopy. Further, a combination of experimental and computational techniques enabled quantification of the relative strength of spin-phonon coupling of each phonon mode. This analysis demonstrates the effect of thermodynamics and site symmetry on the spin lifetimes of W5+ paramagnetic defects, an important step in the process of reducing decoherence to produce longer-lived qubits.

  PublisherOA PDFDOI

• A General and Modular Approach to Solid-State Integration of Zero-Dimensional Quantum Systems

  Nano Letters · 2025-09-03 · 2 citations

  articleOpen access

  Here, we present an all-electrical readout mechanism for quasi-0D quantum states (0D-QS), such as point defects, adatoms, and molecules, that is modular and general, providing an approach that is amenable to scaling and integration with other solid-state quantum technologies. Our approach relies on the creation of high-quality tunnel junctions via the mechanical exfoliation and stacking of multilayer graphene (MLG) and hexagonal boron nitride (hBN) to encapsulate the target system in an MLG/hBN/0D-QS/hBN/MLG heterostructure. This structure allows for all-electronic spectroscopy and readout of candidate systems through a combination of coulomb and spin-blockade. As a proof of principle, we demonstrate electronic tunneling spectroscopy of point defects in hBN and the molecular qubit vanadyl phthalocyanine. Our approach demonstrates a new pathway for the incorporation of molecules and atomic defects into solid-state quantum devices and circuits along with a readout scheme that does not rely on highly constrained optical processes for photonic readout.

  PublisherOA PDFDOI

• Planar Defect Layers Template a High-Pressure InBi Polymorph

  Journal of the American Chemical Society · 2025-07-16 · 2 citations

  articleSenior authorCorresponding

  The short- and long-range order of III-V materials under high pressure has long been the subject of debate, with advancements in structural characterization leading to significant revisions to the accepted structural models. Despite these revisions, previous high-pressure structural assignments in the In-Bi system include the site-disordered β-Sn structure type, a structure type demonstrated to be nonexistent in analogous III-V systems. While X-ray diffraction is consistent withsite disordering in InBi at high pressure, cluster expansion calculations indicate that disordering requires temperatures above 3000 K. We propose InBi as a model material for studying unique high-pressure planar defects due to its highly anisotropic stress-dependent properties and structure. Specifically, we identify two sets of planar defects that mimic the diffraction pattern of a site disordered β-Sn structure type and are compatible with the calculated disorder barrier. We derive these defects by symmetry relations over crystallographic transitions. Density functional theory calculations of the proposed defects suggest that these defects are stabilized by diminishing interlayer separations with pressure. Further, we find that one of the proposed defects closely resembles a bulk high-pressure phase of InBi, InBi-ϵ, and we assert that the proposed defects order upon heating, acting as a template for InBi-ϵ growth. The proposed defects and their electronic structure provide a basis for the trend of superconducting critical temperature with increasing pressure. These methods for identifying defects are generalizable to other materials with reports of site disorder at high pressure, prompting a broader search for related high-pressure defects.

  PublisherDOI

• Tunable Negative Thermal Expansion in Layered Perovskite Ba₃Zr₂S₇

  Inorganic Chemistry · 2025-05-25 · 3 citations

  article

  We simulated the thermal expansion coefficient (TEC) of the layered perovskite sulfide Ba3Zr2S7 (P42/mnm symmetry) from first principles. The calculated ambient pressure and room-temperature volumetric TEC is 38 × 10–6 K–1, which makes the material suitable for use in conventional PV devices. We further predicted low-temperature, pressure-tunable negative thermal expansion (NTE) in Ba3Zr2S7 that arises from a quasi-2D vibration mechanism shared by other n = 2 Ruddlesden–Popper oxides Ca3Ti2O7, Ca3Zr2O7, and Sr3Zr2O7. We computationally found a pressure-induced phase transition to a structure in the monoclinic crystal system. Experimental investigation of this system as a function of pressure supported by in situ diffraction studies in a diamond anvil cell confirmed a phase change at high pressures to a new polymorph that likely exhibits P2/c symmetry. Our simulations show that the quasi-2D mechanism and proximity to a mechanochemical transition enhance the NTE response. These features may be used to design NTE in other layered perovskites.

  PublisherDOI

• Correction to “Chemical Design of Spin Frustration to Realize Topological Spin Glasses”

  Journal of the American Chemical Society · 2025-01-06

  erratumSenior authorCorresponding
  PublisherDOI

• Chemical Design of Spin Frustration to Realize Topological Spin Glasses

  Journal of the American Chemical Society · 2024-10-09 · 3 citations

  articleSenior authorCorresponding

  Patterning spins to generate collective behavior is at the core of condensed matter physics. Physicists develop techniques, including the fabrication of magnetic nanostructures and precision layering of materials specifically to engender frustrated lattices. As chemists, we can access such exotic materials through targeted chemical synthesis and create new lattice types by chemical design. Here, we introduce a new approach to induce magnetic frustration on a modified honeycomb lattice through a competition of alternating antiferromagnetic (AFM) and ferromagnetic (FM) nearest-neighbor interactions. By subtly modulating these two types of interactions through facile synthetic modifications, we created two systems: (1) a topological spin glass and (2) a frustrated spin-canted magnet with low-temperature exchange bias. To design this unconventional magnetic lattice, we used a metal–organic framework (MOF) platform, Ni3(pymca)3X3 (NipymcaX where pymca = pyrimidine-2-carboxylato and X = Cl, Br). We isolated two MOFs, NipymcaCl and NipymcaBr, featuring canted Ni2+-based moments. Despite this similarity, differences in the single-ion anisotropies of the Ni2+ spins result in distinct magnetic properties for each material. NipymcaCl is a topological spin glass, while NipymcaBr is a rare frustrated magnet with low-temperature exchange bias. Density functional theory calculations and Monte Carlo simulations on the NipymcaX lattice support the presence of magnetic frustration as a result of alternating AFM and FM interactions. Our calculations enabled us to determine the ground-state spin configuration and the distribution of spin–spin correlations relative to paradigmatic kagomé and triangular lattices. This modified honeycomb lattice is similar to the electronic Kekulé-O phase in graphene and provides a highly tunable platform to realize unconventional spin physics.

  PublisherDOI

• Symmetry-mediated quantum coherence of $W^{5+}$ spins in an oxygen-deficient double perovskite

  arXiv (Cornell University) · 2024-12-17

  preprintOpen access

  Elucidating the factors limiting quantum coherence in real materials is essential to the development of quantum technologies. Here we report a strategic approach to determine the effect of lattice dynamics on spin coherence lifetimes using oxygen deficient double perovskites as host materials. In addition to obtaining millisecond $T_1$ spin-lattice lifetimes at T ~ 10 K, measurable quantum superpositions were observed up to room temperature. We determine that $T_2$ enhancement in $Sr_2CaWO_{6-δ}$ over previously studied $Ba_2CaWO_{6-δ}$ is caused by a dynamically-driven increase in effective site symmetry around the dominant paramagnetic site, assigned as $W^{5+}$ via electron paramagnetic resonance spectroscopy. Further, a combination of experimental and computational techniques enabled quantification of the relative strength of spin-phonon coupling of each phonon mode. This analysis demonstrates the effect of thermodynamics and site symmetry on the spin lifetimes of $W^{5+}$ paramagnetic defects, an important step in the process of reducing decoherence to produce longer-lived qubits.

  PublisherOA PDFDOI

Frequent coauthors

• Antoine Van Proeyen

  KU Leuven

  39 shared

• Ehud Rivlin

  Kyushu University

  25 shared

• Luis Álvarez-Gaumé

  European Organization for Nuclear Research

  24 shared

• Jiunn-Ming Wang

  Lawrence Berkeley National Laboratory

  21 shared

• Henriette Elvang

  University of Michigan–Ann Arbor

  20 shared

• P. van Nieuwenhuizen

  Stony Brook University

  20 shared

• Eyal Rozenberg

  18 shared

• Massimo Bianchi

  18 shared

Labs

• The Freedman GroupPI

Education

• Ph.D., Chemistry

  University of California, Berkeley

  2009

• A. B., Chemistry

  Harvard University

  2003