Marijn Lucas
A5000227876- Physics of Superconductivity and Magnetism
- Quantum and electron transport phenomena
- Rare-earth and actinide compounds
- Quantum, superfluid, helium dynamics
- Iron-based superconductors research
- Advanced Thermodynamics and Statistical Mechanics
- Topological Materials and Phenomena
- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Theoretical and Computational Physics
- Photonic and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Electron and X-Ray Spectroscopy Techniques
- Advanced Materials Characterization Techniques
- Semiconductor Quantum Structures and Devices
- Cold Atom Physics and Bose-Einstein Condensates
- Advanced Electron Microscopy Techniques and Applications
- Superconducting and THz Device Technology
- Magnetic Properties of Alloys
- Magnetic Properties and Applications
Microsoft (United States)
2025
Royal Holloway University of London
2019-2023
Abstract Quantum circuits interact with the environment via several temperature-dependent degrees of freedom. Multiple experiments to-date have shown that most properties superconducting devices appear to plateau out at T ≈ 50 mK – far above refrigerator base temperature. This is for example reflected in thermal state population qubits, excess numbers quasiparticles, and polarisation surface spins factors contributing reduced coherence. We demonstrate how remove this constraint by operating...
Topological superconductors are essential elements of the periodic table topological quantum matter. However, relevant odd-parity spin-triplet rare. We report high-resolution measurements complex electrical impedance YbRh$_2$Si$_2$ down to 0.4 mK, that reveal presence several superconducting states, suppressed differently by magnetic field, both Pauli-limited and beyond Pauli limit. Superconductivity is abruptly switched off at critical field primary antiferromagnetic order. The onset...
We describe a concrete device roadmap towards fault-tolerant quantum computing architecture based on noise-resilient, topologically protected Majorana-based qubits. Our encompasses four generations of devices: single-qubit that enables measurement-based qubit benchmarking protocol; two-qubit uses braiding to perform Clifford operations; an eight-qubit can be used show improvement operation when performed logical qubits rather than directly physical qubits; and topological array supporting...
Two-dimensional electron gases (2DEGs) with high mobility, engineered in semiconductor heterostructures host a variety of ordered phases arising from strong correlations, which emerge at sufficiently low temperatures. The 2DEG can be further controlled by surface gates to create quasi-one dimensional systems, potential spintronic applications. Here we address the long-standing challenge cooling such electrons below 1 mK, potentially important for identification topological and spin...
The fusion of non-Abelian anyons or topological defects is a fundamental operation in measurement-only quantum computation. In superconductors, this amounts to determination the shared fermion parity Majorana zero modes. As step towards this, we implement single-shot interferometric measurement indium arsenide-aluminum heterostructures with gate-defined nanowire. interferometer formed by tunnel-coupling proximitized nanowire dots. causes state-dependent shift these dots' capacitance up 1 fF....
In the metallic magnet Nb$_{1-y}$Fe$_{2+y}$, low temperature threshold of ferromagnetism can be investigated by varying Fe excess $y$ within a narrow homogeneity range. We use elastic neutron scattering to track evolution magnetic order from Fe-rich, ferromagnetic Nb$_{0.981}$Fe$_{2.019}$ approximately stoichiometric NbFe$_2$, in which we can, for first time, characterise long-wavelength spin density wave state burying quantum critical point. The associated ordering wavevector...
Accessibility to the microkelvin temperature regime is important for quantum technology research. Cryogen-free dilution refrigerators opened up millikelvin range, but perception that ultralow temperatures are difficult reach and require specialist infrastructure. The authors report design of a platform based on nuclear-demagnetization stage, engineered optimized operation cryogen-free refrigerator. study demonstrates as low 395 $\ensuremath{\mu}$K, protocol enables experiments operated below...
The motivation to develop materials for quantum technologies has put exploration of novel states matter at the focus several research fields, with particular efforts towards understanding and controlling behaviour entangled other strongly interacting electronic states. Experimental investigation is primary importance, but requires measurements ultra-low temperatures where interest have long lifetimes. Under these conditions, low energy interactions, such as hyperfine or nuclear exchange...
Electrical and thermal transport were studied in a vacuum-annealed polycrystalline silver wire with residual resistivity ratio 200-400, the temperature range 0.1-1.2K magnetic fields up to 5T. Both at zero field 5T exhibits Wiedemann-Franz law fundamental Lorenz number, contrary an earlier report [Gloos, K. et al, Cryogenics 30, 14 (1990)]. Our result demonstrates that is excellent material for links ultra-low-temperature experiments operating high fields.
Abstract Electrical and thermal transport were studied in a vacuum-annealed polycrystalline silver wire with residual resistivity ratio 200 – 400, the temperature range 0.1 $$-$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mo>-</mml:mo> </mml:math> 1.2 K magnetic fields up to 5 T. Both at zero field T exhibits Wiedemann–Franz law fundamental Lorenz number, contrary an earlier report (Gloos et al., Cryogenics 30:14–18, 1990). Our result demonstrates that is excellent...
Improved accessibility to the microkelvin temperature regime is important for future research in quantum materials; information science; and applications of sensors. Here we report design performance a platform based on nuclear demagnetization stage, engineered well optimized operation standard cryogen-free dilution refrigerator. PrNi5 used as dominant refrigerant. The provides large area mounting experiments an ultralow temperature, low electromagnetic noise environment. characterized using...