Professor Ling has been a Fellow of the American Physical Society since 2005. He joined the faculty of Brown University in 1996. A 1984 graduate of Wuhan University, China, he received his M.S. from the Chinese Academy of Sciences in 1987 and his Ph.D. from the University of Connecticut in 1992. He has done postdoctoral research at Yale University (1992-1994) and the NEC Research Institute at Princeton (1994-1996). He was a visiting professor at Delft University of Technology in the Netherlands from 2002-2003 and a guest professor at Wuhan University from 2002-2005, a Qianren Plan (千人计划) Visiting Professor at Southeast University (Nanjing) from 2015-2018. During 2018-2021, Prof. Ling will be a visiting professor and the founding director for the Institute for Advanced Study at Soochow University in Suzhou, China; as well as a visiting professor in Guangdong University of Technology, Guangzhou, China. Professor Ling received a Research Innovation Award from the Research Corporation in 1998, and he was an A.P. Sloan Fellow from 1998-2001 and a J.S. Guggenheim Fellow from 2002-2003.
|Xia, Deying, Huynh, Chuong, McVey, Shawn, Kobler, Aaron, Stern, Lewis, Yuan, Zhishan, Ling, Xinsheng Sean Rapid fabrication of solid-state nanopores with high reproducibility over a large area using helium ion microscope. Nanoscale/Nanoscale. 2018; 10 : 5198-5204.|
|Luo, X., Stanev, V., Shen, B., Fang, L., Ling, X. S., Osborn, R., Rosenkranz, S., Benseman, T. M., Divan, R., Kwok, W.-K., Welp, U. Antiferromagnetic and nematic phase transitions inBaFe2(As1−xPx)2studied by ac microcalorimetry and SQUID magnetometry. Physical Review B/Phys. Rev. B. 2015; 91 (9)|
|Ling, Daniel Y, Ling, Xinsheng Sean On the distribution of DNA translocation times in solid-state nanopores: an analysis using Schrödinger’s first-passage-time theory. Journal of Physics: Condensed Matter. 2013; 25 (37) : 375102.|
|Kim, Sungcheol, Yu, Lichao, Huang, Stephanie, Pertsinidis, Alexandros, Ling, Xinsheng S. Optical tweezers as a micromechanical tool for studying defects in 2D colloidal crystals. Optical Trapping and Optical Micromanipulation VIII. 2011;|
|Hanson, H. A., Wang, X., Dimitrov, I. K., Shi, J., Ling, X. S., Maranville, B. B., Majkrzak, C. F., Laver, M., Keiderling, U., Russina, M. Structural evidence for an edge-contaminated vortex phase in a Nb crystal using neutron diffraction. Phys. Rev. B. 2011; 84 (1)|
|Wang, Xi, Hanson, Helen A., Ling, Xinsheng Sean, Majkrzak, Charles F., Maranville, Brian B. Three-dimensional spatially resolved neutron diffraction from a disordered vortex lattice. J Appl Cryst. 2011; 44 (2) : 414-417.|
|Venkat S.K. Balagurusamy, Paul Weinger, & Xinsheng Sean Ling Detection of DNA hybridizations using solid-state nanopores. Nanotechnology. 2010; 21 (33) : 335102.|
|Peng, Hongbo, Ling, Xinsheng Sean Reverse DNA translocation through a solid-state nanopore by magnetic tweezers. Nanotechnology. 2009; 20 (18) : 185101.|
|Pertsinidis, Alexandros, Ling, Xinsheng Sean Statics and Dynamics of 2D Colloidal Crystals in a Random Pinning Potential. Phys. Rev. Lett.. 2008; 100 (2)|
|Branton, Daniel, Deamer, David W, Marziali, Andre, Bayley, Hagan, Benner, Steven A, Butler, Thomas, Di Ventra, Massimiliano, Garaj, Slaven, Hibbs, Andrew, Huang, Xiaohua, Jovanovich, Stevan B, Krstic, Predrag S, Lindsay, Stuart, Ling, Xinsheng Sean, Mastrangelo, Carlos H, Meller, Amit, Oliver, John S, Pershin, Yuriy V, Ramsey, J Michael, Riehn, Robert, Soni, Gautam V, Tabard-Cossa, Vincent, Wanunu, Meni, Wiggin, Matthew, Schloss, Jeffery A The potential and challenges of nanopore sequencing. Nat Biotechnol. 2008; 26 (10) : 1146-1153.|
|Daniilidis, N. D., Park, S. R., Dimitrov, I. K., Lynn, J. W., Ling, X. S. Emergence of Quasi-Long-Range Order below the Bragg Glass Transition. Phys. Rev. Lett.. 2007; 99 (14)|
|Daniilidis, Nikolaos, Dimitrov, Ivo, Ling, Xinsheng Sean Ewald construction and resolution function for rocking-curve small-angle neutron scattering experiments. J Appl Cryst. 2007; 40 (5) : 959-963.|
|Park, Sang Ryul, Peng, Hongbo, Ling, Xinsheng S. Fabrication of Nanopores in Silicon Chips Using Feedback Chemical Etching. Small. 2007; 3 (1) : 116-119.|
|Daniilidis, N. D., Dimitrov, I. K., Mitrović, V. F., Elbaum, C., Ling, X. S. Magnetocaloric studies of the peak effect in Nb. Phys. Rev. B. 2007; 75 (17)|
|Dimitrov, I. K., Daniilidis, N. D., Elbaum, C., Lynn, J. W., Ling, X. S. Peak Effect in Polycrystalline Vortex Matter. Phys. Rev. Lett.. 2007; 99 (4)|
|Wu, Shanshan, Park, Sang Ryul, Ling, Xinsheng Sean Lithography-Free Formation of Nanopores in Plastic Membranes Using Laser Heating. Nano Letters. 2006; 6 (11) : 2571-2576.|
|Ling, Xinsheng Sean Dislocation dynamics: Scars on a colloidal crystal ball. Nature Materials. 2005; 4 (5) : 360-361.|
|Storm, A. J., Chen, J. H., Ling, X. S., Zandbergen, H. W., Dekker, C. Electron-beam-induced deformations of SiO[sub 2] nanostructures. J. Appl. Phys.. 2005; 98 (1) : 014307.|
|Pertsinidis, Alexandros, Ling, Xinsheng Sean Video microscopy and micromechanics studies of one- and two-dimensional colloidal crystals. New Journal of Physics. 2005; 7 : 33-33.|
|Storm, A. J., Chen, J. H., Ling, X. S., Zandbergen, H. W., Dekker, C. Fabrication of solid-state nanopores with single-nanometre precision. Nature Materials/Nature Materials. 2003; 2 (8) : 537-540.|
|Pertsinidis, Alexandros, Ling, X. S. Diffusion of point defects in two-dimensional colloidal crystals. Nature/J. Geophys. Res.. 2001; 413 (6852) : 147-150.|
|Pertsinidis, Alexandros, Ling, X. S. Equilibrium Configurations and Energetics of Point Defects in Two-Dimensional Colloidal Crystals. Physical Review Letters/Phys. Rev. Lett.. 2001; 87 (9)|
|Ling, X. S., Park, S. R., McClain, B. A., Choi, S. M., Dender, D. C., Lynn, J. W. Superheating and Supercooling of Vortex Matter in a Nb Single Crystal: Direct Evidence for a Phase Transition at the Peak Effect from Neutron Diffraction. Physical Review Letters/Phys. Rev. Lett.. 2001; 86 (4) : 712-715.|
|Ling, X.S., Smullin, S.J., Berger, J.E., Karlin, W.L., Prober, D.E., Liang, Ruixing Equilibrium and driven vortex phases in the anomalous peak effect. Philosophical Magazine Letters. 1999; 79 (6) : 399-407.|
|Shi, Jing, Ling, X. S., Liang, Ruixing, Bonn, D. A., Hardy, W. N. Giant peak effect observed in an ultrapureYBa2Cu3O6.993crystal. Physical Review B/Phys. Rev. B. 1999; 60 (18) : R12593-R12596.|
|Ling, X. S., Berger, J. E., Prober, D. E. Nature of vortex lattice disordering at the onset of the peak effect. Physical Review B/Phys. Rev. B. 1998; 57 (6) : R3249-R3252.|
|Ling, X. S., Lezec, H. J., Higgins, M. J., Tsai, J. S., Fujita, J., Numata, H., Nakamura, Y., Ochiai, Y., Tang, Chao, Chaikin, P. M., Bhattacharya, S. Nature of Phase Transitions of Superconducting Wire Networks in a Magnetic Field. Physical Review Letters/Phys. Rev. Lett.. 1996; 76 (16) : 2989-2992.|
|X.S. Ling, J.D. McCambridge, N.D. Rizzo, J.W. Sleight, D.E. Prober, L.R. Motowidlo, and B.A. Zeitlin Fluctuation Effects on a Strongly Pinned Vortex Lattice in a Thin Type-II Superconducting Wire. Physical Review Letters . 1995; 74 (Vol. 74, Iss. 5 — 30 January 1995) : 805.|
|Field, Stuart, Witt, Jeff, Nori, Franco, Ling, Xinsheng Superconducting Vortex Avalanches. Physical Review Letters/Phys. Rev. Lett.. 1995; 74 (7) : 1206-1209.|
|X. Ling and J.I. Budnick AC Magnetic Susceptibility Studies of Type-II Superconductors: Vortex Dynamics. 1991; : 377.|
Experimental Condensed Matter Physics:
Superconductivity: the low-temperature properties of solid-state systems with exotic properties such as superconductivity, peak effect, dissipative mechanisms.
Colloid Physics: I plan to re-visit the 2D melting problem using colloidal particles.
Nanobiophysics: I'm currently fascinated by DNA and RNA polymerases' amazing ability in discriminating between bases with astonishing accuracy. This "proofreading" ability of biological micromachines is well beyond what was allowed by equilibrium thermodynamics of the specific Watson-Crick pairing energies, as first pointed out by physicist John Hopfield in the 1970s. Hopfield, and later Ninio, suggested the concept of "kinetic proofreading". My current interest is to build solid-state devices capable of kinetic proofreading functions.
Nanopore DNA Sequencing: kinetic proofreading
After a sabbatical leave at Delft in the 02-03 academic year, I ventured into the field of nanopore DNA sequencing. I was intrigued by the proposal by John Kasianowiz and coworkers that one may use electrical current variations of a nanopore during DNA translocation (linear motion) to sequence a DNA. After more than a decade spent in studying this problem, I came to the realization that in order for us to develop a DNA sequencing technology without polymerase, we need to develop a nanopore device capable of two key functions of a DNA polymerase: suppression of diffusion and base discrimination beyond equilibrium thermodynamics, i.e. kinetic proofreading. We are currently developing a solid-state nanopore sandwich device for this task in collaboration with Soochow University (Suzhou, China), SEU (Nanjing, China) and GUT (Guangzhou, China):
Deying Xia, Chuong Huynh, Shawn McVey, Aaron Kobler, Lewis Stern, Zhishan Yuan and Xinsheng Sean Ling, “Rapid fabrication of solid-state nanopores with high reproducibility over a large area using a helium ion microscope”, Nanoscale, 10, 5198-5204 (2018).
Daniel Y. Ling and Xinsheng Sean Ling, "On the distribution of DNA translocation times in solid-state nanopores: an analysis using Schrödinger's first-passage-time theory", J. Phys.: Cond. Matt. 25, 375102 (2013).
Xinsheng Sean Ling, "METHODS OF SEQUENCING NUCLEIC ACIDS USING NANOPORES AND ACTIVE KINETIC PROOFREADING", World Intellectual Property Organization, WO2013/119784 A1 (http://patentscope.wipo.int/search/en/WO2013119784)
Xinsheng Sean Ling, "Solid-State Nanopores: Methods of Fabrication and Integration, and Feasibility Issues in DNA Sequencing", p.177 in S.M. Iqbal and R. Bashir (eds.), Nanopores: Sensing and Fundamental Biological Interactions, DOI 10.1007/978-1-4419-8252-0_8, Springer Science+Business Media, LLC 2011
Venkat S.K. Balagurusamy, Paul Weinger, & Xinsheng Sean Ling, "Detection of DNA hybridizations using solid-state nanopores", Nanotechnology 21, 335102 (2010).
Hongbo Peng and X.S. Ling, "Reverse DNA translocation through a solid-state nanopore by magnetic tweezers", Nanotechnology, 20, 185101(2009).
Sang R. Park, H. Peng, and X.S. Ling, "Fabrication of Nanopores in Silicon Chips Using Feedback Chemical Etching", SMALL 3, 116 (2007).
Shanshan Wu, Sang R. Park, and X.S. Ling, "Lithography-Free Formation of Nanopores in Plastic Membranes using Laser Heating", Nano Letters 6, 2571(2006).
A.J. Storm, J.H. Chen, X.S. Ling, H. Zandbergen, and C. Dekker, "Electron-Beam-Induced Deformations of SiO2 Nanostructures", Journal of Applied Physics 98, 014307 (2005).
Arnold J. Storm, Jiang Hua Chen, X.S. Ling, H. Zandbergen, and C. Dekker, "Fabrication of Solid-State Nanopores with Single Nanometer Precision", Nature Materials, 2, 537 (2003).
Colloid Physics: defects and 2D melting
2D colloids provide a convenient model system for studying defects and order in condensed matter physics. We pioneered the method of using optical tweezers to create point defects in a 2D colloidal crystal and taking advantage of the fact that in 2D, point defects can be thermally excited into dislocation pairs, which are topological defects. We were able to observe for the first time the famous "Peierls barrier" proposed by Rudolf Peierls 70 years ago but was never observed in a real experiment. We also carried out a random pinning experiment in which we realized experimentally a "2D solid in random pinning potentials" which was extensively theorized. We showed that the quasi-long-range order (QLRO) of a 2D crystal is destroyed by random pinning, and the system behaves as a "pinned liquid". Upon application of a driving force, instead of depin the system from the random potential, thereby causing the system to re-crystalize, we found that the system exhibits the classic thermally activated creep phenomena, i.e. a slow liquid.
In collaboration with Prof. Zexin Zhang of Soochow University, we are currently setting up a large scale 2D melting experiment using mondispersed colloidal particles of various inter-particle interactions to address a longstanding question regarding the nature of 2D melting, first order vs. KTHNY (Kosterlitz-Thouless-Halperin-Nelson-Young).
Alexandros Pertsinidis and X.S. Ling, "Statics and Dynamics of 2D Colloidal Crystals in a Random Pinning Potential", Physical Review Letters, 100, 028303 (2008).
A. Pertsinidis and X.S. Ling, "Equilibrium Configurations and Energetics of Point Defects in Two-Dimensional Colloidal Crystals", Physical Review Letters, 87, 098303 (2001).
A. Pertsinidis and X.S. Ling, "Diffusion of Point Defects in Two-Dimensional Colloidal Crystals", Nature, 413, 147 (2001).
Vortex Physics: peak effect and Bragg glass phase
Vortex lines in type-II superconductors form a condensed matter system with long-range order in competition with random potentials. In 1991, while being a graduate student with Prof. J.I. Budnick, I discovered the so-called "peak effect" in high-Tc superconductors. This peak effect was ultimately proven, first by our group at Brown (S.R. Park, et al., using smal angle neutron scattering in collaboration with J. Lynn at NIST), to be a genuine phase transition between a topologically ordered "Bragg glass" and a disordered phase. The topologically ordered 3D Bragg glass phase is reminiscent of the QLRO discovered by J.M. Kosterlitz and D.J. Thouless in 2D X-Y model and Haldane's in 1D quantum spin chain models, it was long thought not possible due to a well-known and powerful Larkin-Imry-Ma theorem which states that any system, below 4D, with broken continuous symmetry cannot have LRO with any amount of random fields. It turns out that, like the Mermin-Wagner theorem for 2D X-Y, the Larkin-Imry-Ma theorem cannot be applied simply to the destruction of the topological order in a 3D vortex-line lattice.
I have a renewed interested in the vortex phase diagram, this time in the newly discovered topological superconductors.
N. D. Daniilidis, S. R. Park, I. K. Dimitrov, J. W. Lynn, X. S. Ling, "Emergence of Quasi-Long-Range Order below the Bragg Glass Transition", Physical Review Letters, 99, 147007 (2007).
I. K. Dimitrov, N. D. Daniilidis, C. Elbaum, J. W. Lynn, X. S. Ling, “Peak Effect in Polycrystalline Vortex Matter” Physical Review Letters, 99, 047001 (2007).
N. D. Daniilidis, I. K. Dimitrov, V. F. Mitrovic, C. Elbaum, X. S. Ling, “Magnetocaloric Studies of the Peak Effect in Nb”, Physical Review B 75, 174519 (2007).
S.R. Park, S.M. Choi, D.C. Dender, J.W. Lynn, and X.S. Ling, “Fate of the Peak Effect in a Type-II Superconductor: Multicriticality of the Bragg-Glass Transition", Physical Review Letters, 91, 167003 (2003).
X.S. Ling, S.R. Park, B.A. McClain, S.M. Choi, D.C. Dender, and J.W. Lynn, "Superheating and Supercooling of Vortex Matter in a Nb Single Crystal: Direct Evidence for a Phase Transition at the Peak Effect from Neutron Diffraction", Physical Review Letters, 86, 712 (2001).
J. Shi, X. S. Ling, R. Liang, D.A. Bonn, W.N. Hardy, "Giant Peak Effect Observed in an Ultra-pure YBa2Cu3O7 Crystal", Physical Review, B Rapid Communications, 60, R12593 (1999).
X.S. Ling, J.E. Berger, and D. E. Prober, "Nature of Vortex Lattice Disordering at the Onset of the Peak Effect", Physical Review, B Rapid Communications, 57, R3249 (1998).
X.S. Ling, J.I. Budnick, and B.W. Veal, "Peak Effect and Its Disappearance in Superconducting YBCO Crystals", Physica C, 282, 2191 (1997).
C. Tang, X.S. Ling, S. Bhattacharya, and P.M. Chaikin, "Peak Effect in Superconductors: Melting of Larkin Domains", Europhysics Letters, 35, 597 (1996).
X. S. Ling, "Flux dynamics in high-temperature superconductors", (Ph.D. thesis, University of Connecticut, May 1992), reprints available from UMI Microfilm.
X.S. Ling and J.I. Budnick, "AC Magnetic Susceptibility Studies of Type-II Superconductors: Vortex Dynamics", in Magnetic Susceptibility of Superconductors and Other Spin Systems, Edited by R.A. Hein, T.L. Francavilla, & D.H. Liebenberg, (Plenum, New York, 1991), p.377.
Vortex Physics: 2D superconducting periodic wire networks
A 2D periodic Nb wire network in a perpendicular magnetic field is a realization of frustrated X-Y models:(1) At f=1/2, the system has both broken U(1) and Z2 symmetries, as such we expect both Kosterlitz-Thouless and Ising transitions. The question was whether the two transitions occur at the same temperature. My experiment at NEC (with S. Bhattacharya and P.M. Chaikin) showed that the two occur at the same temperature. (2) At f=2/5, the theory predicted a first-order transition; At f=0.618, the theory predicted no transition. My experiment showed that in both cases the system exhibits the features of a continuous transition.
I'm actively looking into ways to develop new lithographic techniques to produce large scale 2D superconducting wire networks. When such technique becomes available, it is likely we will revisit some of the unresolved problems in frustrated 2D XY systems.
X.S. Ling, H.J. Lezec, M.J. Higgins, J.S. Tsai, J. Fujita, Y. Nakamura, Chao Tang, P.M. Chaikin, and S. Bhattacharya, Physical Review Letters, 76, 2989 (1996), “Nature of Phase Transitions of Superconducting Wire Networks in a Magnetic Field".
Vortex Physics: finite-size effect of a vortex glass phase
NbTi wires are dirty type-II superconductors. In a strong magnetic field, the vortex phase is that of a vortex glass, a structurally disordered vortex lines phase with divergent activation barrier for vortex creep. The Fisher-Fisher-Huse theory of vortex glass implied that for a finite-size system, there should be ohmic resistance determined by the sample size, which indeed was observed in our experiment. (I was a postdoc under Professor D.E. Prober at Yale University where this work was finished.)
X.S. Ling, J.D. McCambridge, N.D. Rizzo, J.W. Sleight, D.E. Prober, L.R. Motowidlo, and B.A. Zeitlin, Physical Review Letters, 74, 805 (1995), “Fluctuation Effects on a Strongly Pinned Vortex Lattice in a Thin Type-II Superconducting Wire”.
X.S. Ling, J.D. McCambridge, N.D. Rizzo, J.W. Sleight, D.E. Prober, L.R. Motowidlo, and B.A. Zeitlin, Physica B, 194-196, 1867 (1994), “Flux Dynamics in Submicron Superconducting NbTi Wires”.
Vortex Physics: vortex avalanches in the Bean critical state
NbTi tube provides an excellent system for studying vortex avalanches in the Bean critical state. The question was whether such a system exhibits the "self-organized criticality" proposed in the famous Bak-Tang-Wiesenfeld sandpile model since we can make the system thermally stable and vortices are known to have no inertia effects (the real sand particles do). Stuart Field (at Michigan at the time, now at Colorado State) and I (at Yale at the time) joined the forces in making the experiment successful (I made the NbTi tube sample at Yale and his student Jeff Witt built the amplifier, the measurements were done at Michigan).
S. Field, J. Witt, F. Nori, and X.S. Ling, Physical Review Letters, 74, 1206 (1995), “Superconducting Vortex Avalanches”.
|1992||PhD||University of Connecticut|
|1987||MS||Chinese Academy of Sciences|
千人计划Visiting Professor at Southeast University (Nanjing) (2015-2018)
Fellow, American Physical Society (2005)
Guggenheim Fellow (2002)
Alfred P. Sloan Fellow (1998)
Research Innovation Awards, Research Corporation (1998)
Institute for Advanced Study at Soochow University, Suzhou, China (Visiting Professor and Director, 2018-2021)
Guangdong University of Technology, Guangzhou, China (Visiting Professor, 2018-2021)
American Physical Society (Fellow, Life Member)
OCPA (Life Member)
|PHYS 0560 - Experiments in Modern Physics|
|PHYS 0790 - Physics of Matter|
|PHYS 1510 - Advanced Electromagnetic Theory|