LABORATORY FOR

PHYSICAL SCIENCES

8050 Greenmead Drive,

College Park, MD 20740

Phone: (301) 935-6400

Fax: (301) 935-6723

Email: info@lps.gov

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The Solid State and Quantum Physics (SSQP) research program conducts experimental and theoretical research focused on quantum and cryogenic devices, and associated information theory.  Our research groups are active in the broad research community and collaborate with academia, industry, and national laboratories. SSQP also supports research externally and is a founding member of the Joint Quantum Institute.  Contact us.

The epitaxial materials group synthesizes advanced materials using molecular beam epitaxy.  Experimental activities revolve around creating materials that advance the capabilities of qubit devices.  Two examples are custom low-loss superconductors and semiconductor quantum well heterostructures.

EPITAXIAL MATERIALS RESEARCH

The scanning tunneling microscopy (STM) group utilized unique systems capable of measuring devices at cryogenic temperatures and in high magnetic fields, and performing ultra-precise lithography.  Experimental research activities focus on exploring the surfaces of superconductors, magnetic thin films, and performing hydrogen lithography to synthesize devices at the atomic scale.

ATOMISTIC FABRICATION RESEARCH

The quantum superconducting devices group measures at very low temperatures (T ~ 20 mK) a variety of quantum phenomena in circuit QED transmon devices. Our work is broadly focused on understanding 1) the physics of quantum coherent phenomena in these devices and their potential application for quantum computation and 2) the sources of noise that couple to our devices and developing mitigation strategies in an effort to improve the device’s coherence time and control fidelities.

We also develop novel control techniques on superconducting devices so that exotic quantum states can be created. Find out more.

QUANTUM SUPERCONDUCTING DEVICES RESEARCH

  Our primary focus is the development of novel materials and technologies for quantum computer research.  Motivated by our previous theoretical work on silicon quantum computer architectures, we are exploring novel approaches to creating semiconductor devices at the atomic scale: we have fabricated and measured the first silicon field effect transistor (FET) devices in which mobile electrons are confined adjacent to a hydrogen terminated silicon surface. These devices have record mobility and exhibit the sixfold valley degeneracy expected on silicon [111].  We have recently extended this technique to hole systems and have observed the fractional quantum Hall effect (FQHE) in a very high mobility electron device. In a separate project, we are applying the technologies being developed for ion trap quantum computing to isolate and characterize flakes of levitated spinning graphene. Find out more.  

SILICON QUANTUM DEVICES AND 2D SYSTEMS

Custom superconducting resonators and qubits are studied to better understand coherence, noise, quantum-material properties, et cetera for the future quantum processors. Many studies are performed on atomically sized two-level systems (TLSs), a major source of decoherence. For example, TLS-energy tuning and TLS-sourced microwave lasing are implemented. In other studies, macroscopic-quantum phenomena with flux-quanta are explored to lower the energy usage of digital gates in computers. Present-day logic gates use irreversible functions, but physics allows for fundamentally more-efficient reversible gates. Free-dynamical reversible gates are possible using systems of undamped Josephson junctions with complex resonances. Ongoing theoretical and experimental studies of these resonances may lead to dissipationless changes in flux-quanta polarity for the future of computing. Find out more.

QUANTUM CIRCUITS WITH TWO-LEVEL SYSTEMS & REVERSIBLE LOGIC

We study a number of topics including developing resource reduction methods for quantum error correcting codes; quantum algorithms for problems in group theory and combinatorics, and quantum simulation algorithms for non-linear classical systems; and quantum control protocols for the preparation of high-fidelity logical quantum states.

QUANTUM INFORMATION THEORY RESEARCH

Can we design qubits with longer coherence times?  Is it possible for a time-independent Hamiltonian to prevent noise from decohering a quantum computation?  Are there fundamental physical limits to quantumness?  These are some of the research questions studied by our group. Find out more.

FUNDAMENTALS OF QUBIT BEHAVIOUR

We propose new types of qubits and quantum devices for practical application from quantum computing to sensing and for advancing fundamental physics. Collaborating with experimental groups around the world we seek to understand and advance the state of the art in qubit science. Find out more.

QUANTUM INFORMATION AND DEVICE THEORY

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