# Daniel J. Gauthier

### Bass Fellow

Prof. Gauthier is interested in a broad range of topics in the fields of nonlinear and quantum optics, and nonlinear dynamical systems.

In the area of optical physics, his group is studying the fundamental characteristics of highly nonlinear light-matter interactions at both the classical and quantum levels and is using this understanding to develop practical devices.

At the quantum level, his group has three major efforts in the area of quantum communication and networking. In one project, they are investigating hybrid quantum memories where one type of memory is connected to another through the optical field (so-called flying qubits). In particular, they are exploring nonlinear optical methods for frequency converting and impedance matching photons emitted from one type of quantum memory (e.g., trapped ions) to another (e.g., quantum dots).

In another project, they are exploring methods for efficiently transmitting a large number of bits of information per photon. They are encoding information on the various photon degrees of freedom, such as the transverse modes, one photon at a time, and using efficient mode sorters to direct the photons to single-photon detectors. The experiments make use of multi-mode spontaneous down conversion in a nonlinear crystal to produce quantum correlated or entangled photon pairs.

Another recent interest is the development of the world's most sensitive all-optical switch. Currently, they have observed switching with an energy density as low as a few hundred yoctoJoules per atomic cross-section, indicating that the switch should be able to operate at the single-photon level. The experiments use a quasi-one-dimensional ultra-cold gas of rubidium atoms as the nonlinear material. They take advantage of a one-dimensional optical lattice to greatly increase the nonlinear light-matter interaction strength.

In the area of nonlinear dynamics, his group is interested in the control and synchronization of chaotic devices, especially optical and radio-frequency electronic systems. They are developing new methods for private communication of information using chaotic carriers, using chaotic elements for distance sensing (e.g., low-probability-of-detection radar), using networks of chaotic elements for remote sensing, and using chaotic elements for generating truly random numbers at high data rates. Recently, the have observed 'Boolean chaos,' where complex behavior is observed in a small network of commercially-available free-running logic gates.

###### Appointments and Affiliations

- Bass Fellow
- Robert C. Richardson Professor of Physics
- Professor of Physics
- Professor in the Department of Electrical and Computer Engineering
- Interim Chair in the Department of Physics

###### Contact Information:

**Office Phone:**(919) 660-2511**Web Page:**

###### Education:

- Ph.D. University of Rochester, 1989
- M.S. University of Rochester, 1983
- B.S. University of Rochester, 1982

###### Research Interests:

Prof. Gauthier is interested in a broad range of topics in the fields of nonlinear and quantum optics, and nonlinear dynamical systems.

In the area of optical physics, his group is studying the fundamental characteristics of highly nonlinear light-matter interactions at both the classical and quantum levels and is using this understanding to develop practical devices.

At the quantum level, his group has three major efforts in the area of quantum communication and networking. In one project, they are investigating hybrid quantum memories where one type of memory is connected to another through the optical field (so-called flying qubits). In particular, they are exploring nonlinear optical methods for frequency converting and impedance matching photons emitted from one type of quantum memory (e.g., trapped ions) to another (e.g., quantum dots).

In another project, they are exploring methods for efficiently transmitting a large number of bits of information per photon. They are encoding information on the various photon degrees of freedom, such as the transverse modes, one photon at a time, and using efficient mode sorters to direct the photons to single-photon detectors. The experiments make use of multi-mode spontaneous down conversion in a nonlinear crystal to produce quantum correlated or entangled photon pairs.

Another recent interest is the development of the world's most sensitive all-optical switch. Currently, they have observed switching with an energy density as low as a few hundred yoctoJoules per atomic cross-section, indicating that the switch should be able to operate at the single-photon level. The experiments use a quasi-one-dimensional ultra-cold gas of rubidium atoms as the nonlinear material. They take advantage of a one-dimensional optical lattice to greatly increase the nonlinear light-matter interaction strength.

In the area of nonlinear dynamics, his group is interested in the
control and synchronization of chaotic devices, especially optical and
radio-frequency electronic systems. They are developing new
methods for private communication of information using chaotic
carriers, using chaotic elements for distance sensing (e.g.,
low-probability-of-detection radar), using networks of chaotic elements
for remote sensing, and using chaotic elements for generating truly
random numbers at high data rates. Recently, the have observed 'Boolean chaos,' where complex behavior is observed in a small network of commercially-available free-running logic gates.

###### Specialties:

Atomic, molecular, and optical physics

Heart, Electrophysiology

Experimental condensed matter physics

Nonlinear dynamics and complex systems

###### Awards, Honors, and Distinctions:

- Robert C. Richardson Professor of Physics. Duke University. 2011
- Outstanding Referee of the Physical Review and Physical Review Letters. American Physical Society. 2009
- Fellows. Optical Society of America. 2006
- Fellow. American Physical Society. 2002

###### Courses Taught:

- PHYSICS 142L9: General Physics II (LAB)
- PHYSICS 142L9D: General Physics II (Discussion)
- PHYSICS 142L: General Physics II
- PHYSICS 493: Research Independent Study

###### Representative Publications: (More Publications)

- Gauthier, DJ; Schmittberger, BL,
*Enhancing the nonlinearity at ultra-low light levels using spatial bunching of cold atoms*(2015) [abs]. - Gauthier, DJ; Haynes, ND; Lohmann, J; D'Huys, O; Rosin, DP,
*Extreme transients in time-delay autonomous Boolean networks*(2015) [abs]. - Gauthier, DJ; Haynes, ND; Soriano, MC; Rosin, DP; Fischer, I,
*Physical reservoir computing with Boolean logic*(2015) [abs]. - Gauthier, DJ; Lohmann, J; Haynes, ND; D'Huys, O; Schöll, E,
*Dynamics of experimental time-delay autonomous Boolean networks*(2015) [abs]. - Rosin, DP; Rontani, D; Haynes, ND; Schöll, E; Gauthier, DJ,
*Transient scaling and resurgence of chimera states in networks of Boolean phase oscillators.*, Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, vol 90 no. 3 (2014) [10.1103/physreve.90.030902] [abs].

###### Lectures and Invited Talks:

- Toward Single-Photon Nonlinear Optics via Self-Assembled Ultracold Atoms, Frontiers in Optics 2010/Division of Laser Science XXVI, Rochester, NY,
- 'High throughput, high bit-per-photon quantum communication, QIBEC (Quantum Information/BEC) Seminar, NIST, Gaithersburg, MD,
- 'Using self-assembly to enable single-photon nonlinear optics, EECS Distinguished Seminar Series, Northwestern University,
- Observation of chaos in small networks of Boolean-like logic circuits, SCCAMM Workshop on Nonlinear Dynamics of Networks, University of Maryland, College Park, MD,
- Slow light applications of forward stimulated Brillouin scattering, Photonics West, San Francisco, CA,
- Boolean Chaos, Dynamics Days 2010, Chicago, IL,
- Boolean Delay Systems, Workshop on Delayed Complex Systems, Max-Planck Institute for the Physics of Complex Systems, Dresden, Germany,
- Slow and stopped light in optical waveguides, DTU Fotonik Seminar, Danmarks Tekniske Universitet, Bygning, Denmark,
- Broadband chaos in time-delay photonic and electroic devices: Potential implications for sensor networks, Nonlinear Dynamics Seminar, University of Maryland, College Park, MD,
- Ultra-low-light-level all-optical switching, Physics Department Colloquium, Ohio University, Athens, OH,
- Discovery of a new type of bifurcation in paced cardiac muscle, Third Workshop Promotionskolleg, Helmholtz Center for Brain and Mind Dynamics, Liebenwalde, Germany,