Dr Jan Mol
Department of Materials
Tel: +44 1865 273719 (Room 195.20.09)
My research is focussed on understanding quantum phenomena in atomic- and molecular-scale electronic devices. Recent advances in nanofabrication now make it possible to measure the quantum properties of individual atoms and molecules. The aim of my research is to harness quantum phenomena in single atoms an molecules for real-world applications.
Integrated circuits where each functional unit is formed by only a single molecule will be the ultimate form of electronic device scaling. I measure charge transport through individual molecules in reproducible graphene-molecule-graphene transistors that operate up to room temperature.
Dopant atoms in semiconductors form a natural confinement potential for electrons or holes. I study the quantum mechanical properties of individual donor and acceptor atoms embedded in state-of-the-art nanoscale silicon transistors. This research focusses on the manipulation and read-out of spin- and charge-states of single dopant atoms.
Y. Li, J.A. Mol, S.C. Benjamin G.A.D. Briggs, Interferecne-based molecular transistors. Sci. Rep. just accpeted (2016)
P. Gehring, H. Sadeghi, S. Sangtarash, C.S. Lau, J. Liu, A. Ardavan, J.H. Warner, C.J. Lambert, G.A.D. Briggs, and J.A. Mol, Quantum Interference in Graphene Nanoconstrictions. Nano Lett. 16(7), 4210 (2016)
J. Salfi, J.A. Mol, R. Rahman, G. Klimeck, M.Y. Simmons, L.C.L. Hollenberg, and S. Rogge, Quantum simulation of the Hubbard model with dopant atoms in silicon. Nature Comm. 7:11342 (2016)
J. Salfi, J.A. Mol, D. Culcer, and S. Rogge, Charge-Insensitive Single-Atom Spin-Orbit Qubit in Silicon. Phys. Rev. Lett. 116, 246801 (2016)
C.S. Lau, H. Sadeghi, G. Rogers, S. Sangtarash, P. Dallas, K. Porfyrakis, J.H. Warner, C.J. Lambert, G.A.D. Briggs, and J.A. Mol, Redox-dependent Franck-Condon blockade and avalanche transport in a graphene-fullerene single-molecule transistor. Nano Lett. 16(1), 170 (2016)
P. Puczkarski, P. Gehring, C.S. Lau, J. Liu, A. Ardavan, J.H. Warner, G.A.D. Briggs, and J.A. Mol, Three-terminal graphene single-electron transistor fabricated using feedback-controlled electroburning. Appl. Phys. Lett. 107, 133105 (2015)
J.A. Mol, C.S. Lau, W.J.M. Lewis, H. Sadeghi, C. Roche, A. Cnossen, J.H. Warner, C.J. Lambert, H.L. Anderson, and G.A.D. Briggs, Graphene-porphyrin single-molecule transistors, Nanoscale 7. 13181 (2015)
J.A. Mol, J. Salfi, R. Rahman, Y. Hsueh, J.A. Miwa, G. Klimeck, M.Y. Simmons, and S. Rogge, Interface-induced heavy-hole/light-hole splitting of acceptors in silicon. Appl. Phys Lett. 106, 203110 (2015)
H. Sadeghi, J.A. Mol, C.S. Lau, G.A.D. Briggs, J. Warner, and C.J. Lambert, Conductance enlargement in picoscale electroburnt graphene nanojunctions. Proc. Natl. Acad. Sci. 112, 2658 (2015)
C.S. Lau, J.A. Mol, J.H. Warner and G.A.D. Briggs, Nanoscale control of graphene electrodes. Phys. Chem. Chem. Phys. 16 20398 (2014)
J. Salfi, J.A. Mol, R. Rahman, G. Klimeck, M.Y. Simmons, L.C.L. Hollenberg and S. Rogge, Spatially resolving valley quantum interference of a donor in silicon. Nature Mater. 13, 605 (2014)
J. van der Heijden, J. Salfi, J.A. Mol, J. Verduijn, G.C. Tettamanzi, A.R. Hamilton, N. Collaert, S. Rogge, Probing the spin states of a single acceptor atom. Nano Lett. 14(3), 1492 (2014)
J. Zemen, J. Mašek, J. Ku?era, J. A. Mol, P. Motloch, T. Jungwirth, Comparative study of tight-binding and ab initio electronic structure calculations focused on magnetic anisotropy in ordered CoPt alloy. J. of Magn. Magn. Mater. 356, 87 (2014)
J.A. Miwa, J.A. Mol, J.Salfi, M. Simmons, S. Rogge, Transport through a single donor in p-type silicon. Appl. Phys. Let. 103, 043106 (2013)
J.A. Mol, J. Salfi, J.A. Miwa, M.Y. Simmons, S. Rogge, Interplay between dielectric mismatch and quantum confinement for ultrashallow dopants. Phys. Rev. B. 87, 245471 (2013)
B. Fresch, J. Verduijn, J.A. Mol, S. Rogge and F. Remacle, Querying a quasi- classical Oracle: One bit function identification problem implemented in a single atom transistor. EPL (Europhysics Letters) 99, 28004 (2012)
J.A. Mol, J. van der Heijden, J. Verduijn, M. Klein, F. Remacle, S. Rogge, Balanced ternary addition using a gated silicon nanowire. Appl. Phys. Lett. 99, 263109 (2011)
J.A. Mol, J. Verduijn,R. D. Levine, F. Remacle,S. Rogge, Integrated logic circuits using single-atom transistors. Proc. Natl. Acad. Sci. 108, 13969-13972 (2011)
B.C. Johnson, A.D.C. Alves, S. Thompson, C. Yang, D.N. Jamieson, J. Verduijn, J.A. Mol, G.C. Tettamanzi, S. Rogge, R. Wacquez, M. Vinet, Drain current modulation in a nanoscale MOSFET channel by single dopant implantation. Appl. Phys. Lett. 96, 264102 (2010)
Y. Yan, J.A. Mol, J. Verduijn, S. Rogge, R.D. Levinec, F. Remacle, Electrically addressing a molecule-like donor pair in silicon: An atomic scale cyclable full adder logic. J. Phys. Chem. C 114 20380 (2010)
M. Klein, J.A. Mol, J. Verduijn, G.P. Lansbergen, S. Rogge, R.D. Levine, and F. Remacle, Ternary logic implemented on a single dopant atom field effect silicon transistor. Appl. Phys. Lett., 96, 043107 (2010)
J.A. Mol, S.P.C. Beentjes, S.Rogge, A low temperature surface preparation method for STM nano-lithography on Si(100), Appl. Surf. Sci. 256, 5042 (2010)
M. Klein, G.P. Lansbergen, J.A. Mol, S. Rogge, R.D. Levine, F. Remacle, Reconfigurable logic devices on a single dopant atom - operation up to a full adder by using electrical spectroscopy. ChemPhysChem 10, 162 (2009)
Z. Li, J.A. Mol, L. Lagae, G. Borghs, R. Mertens, and W. Van Roy, Pulsed field induced magnetization switching in (Ga,Mn)As, Appl. Phys. Lett. 92, 112513 (2008)
Quantum interference in single-molecule devices
Dr J. A. Mol, Professor G. A. D. Briggs and Professor H. L. Anderson*
Quantum interference offers a rich resource which could be exploited in molecular devices. If there are multiple pathways for energy transport through a molecule, or if electrical transport is subject to resonances within a molecule, then these effects could be exploited for practical technologies. For example, it may be possible to make transistors with much lower power consumption than current silicon CMOS, and it may be possible to develop improvement of thermovoltaic materials for scavenging heat that would otherwise be wasted. Understanding such phenomena may also shed light on postulated quantum coherent processes in biology, ranging from photosynthesis to bird navigation.
The project will require nanofabrication of carbon-based devices into which individual molecules can be inserted. The current through the molecules will be measured with a view to discovering mechanisms of quantum interference. A major challenge will be to devise and fabricate geometries with additional gates to control the quantum interference. The project will involve nanofabrication, chemical attachment of the molecules, and electrical measurements over a range of temperatures and frequencies, with especial regard to discovering the conditions under which quantum coherence can be found. A successful outcome will be to find regimes in which quantum coherence gives enhanced device performance.
* Department of Chemistry
Silicon quantum electronics
Dr J. A. Mol and Professor G. A. D. Briggs
Quantum information embodied in spins in silicon can be manipulated very precisely, and can persist for over three hours. Quantum computers made from silicon materials would benefit from the great industrial development of silicon processing and nanofabrication. Much of previous research in silicon for quantum computing has used donor impurities in bulk crystals. The great challenges now are to learn how to measure the states and control the interactions of a small numbers of spins in silicon. This project will seek to develop control techniques that will be sufficiently precise to allow fault-tolerant error-correction in silicon devices with small numbers of spins. Scalable quantum technologies will need to meet and surpass certain accuracy thresholds to demonstrate quantum error correction. The goal of the project will be to exceed these thresholds using impurity and quantum dot spins in silicon devices. For this you will investigate magnetic resonance in both many-spin and single-spin regimes. You will need to have, or to acquire early in the project, good knowledge of physics, magnetic resonance, quantum information, and semiconductor materials.
Also see a full listing of New projects available within the Department of Materials.