Author Affiliations
1Collaborative Innovation Center of Advanced Microstructures, National Laboratory of Solid State Microstructures, School of Physics, Nanjing University, Nanjing, Jiangsu 210093, China2Key Laboratory of Artificial Micro- and Nano-Structures of Ministry of Education, School of Physics and Technology, Wuhan University, Wuhan, Hubei 430072, Chinashow less
Fig. 1. Forming artificial lattices. (a) Physical states labeled by consecutive integers; (b) introducing nearest-neighbor coupling between physical states to create a one-dimensional system; (c) introducing a special long-range coupling between physical states to create a two-dimensional system
[56-57] Fig. 2. Using different orbital angular momenta to create a synthetic dimension. (a) A degenerate cavity can be described by a synthetic lattice along the direction of the angular momenta
[58]; (b) a 2D degenerate cavity array
[61]; (c) physical implementation of degenerate cavity
[61] Fig. 3. Using orbital angular momenta to realize quantum walks. (a) Scheme of one-dimensional quantum walk
[65]; (b) experimental scheme of 2D quantum walks
[66] Fig. 4. Using ring resonators to create the synthetic frequency dimension. (a) A ring resonator dynamically modulated by an electro-optic modulator (EOM) can be described by a tight-binding model of a photon along a one-dimensional lattice in the synthetic frequency dimension
[67]; (b) a one-dimensional array of ring resonators can be mapped into a tight-binding model in two-dimension, with the extra dimension being the synthetic frequency dimension
[ Fig. 5. Using ring resonators to create higher synthetic space. (a) A synthetic 3D lattice realized using 2D honeycomb array of ring resonators, each ring is subjected to an index modulation which generates a synthetic frequency dimension
[70]; (b) a sketch of an effective 4D lattice composed of a 3D resonator lattice and one synthetic frequency dimension
[77] Fig. 6. Forming synthetic lattices with finite elements. (a) Two-ring resonators
A and
B, each ring has a phase modulator, in between, there is an auxiliary ring
C with two phase modulators
[57]; (b) a honeycomb lattice on a cylindrical surface with a twisted boundary condition is created when considering long-range coupling in the system in Fig. (a)
[57]; (c) a single optical cavity in
Fig. 7. Using waveguides to create synthetic frequency dimension. (a) Schematic of LiNbO
3 phase modulator
[88]; (b) dispersion curve of optical modes and photonic intraband transitions in the vicinity of
ω0 achieve a one-dimensional lattice formed from waveguide modes at different frequencies
[88]; (c) dynamically adjustable 2D brick-wall lattice waveguide array and an equivalen
Fig. 8. Using nonlinear optical effects to create synthetic frequency dimension. (a) Four-wave mixing Bragg scattering in third-order nonlinear waveguide
[98]; (b) with multiple pumps present (up), evolution of the signal (down) is governed by multiple hopping coefficients across synthetic frequency lattice
[98]; (c) nonlinear Brillouin scattering in a microcavity
[101 Fig. 9. Synthetic modal dimension. (a) Coupling diagram of
x-
θ plane (left) and corresponding
x-
w (OAM) plane (right)
[103]; (b) one-dimensional lattice with a spectrum of eigenmodes with equally spaced propagation constants
[104]; (c) oscillating the lattice in the longitudinal direction causes each eigenmode to couple to its nearest neighbours, forming a lattice of coupled mo
Fig. 10. Mapping multi-dimensional networks to 1D lattices. (a) 1D transformation structure of high-dimensional network based on similarity of Hamiltonian
[106]; (b) mapping high-dimensional networks to 1D lattices
[107] Fig. 11. Using multiple pulses to create synthetic photonic lattice. (a) Two fiber loops with slightly different lengths connected by a 50/50 coupler; (b) an equivalent lattice network that describes a one-dimensional synthetic lattice (n) evolves along the time axis (m)
Fig. 12. Using multiple pulses to realize 2D quantum walks. (a) Experimental setup of a 2D quantum walk
[118]; (b) experimental implementation of 2D quantum walks with time-bin encoding and the mapping between the time-bin sequence and the 2D spatial lattice
[119] Fig. 13. Adiabatic pumping. (a) Sketch of setup for observation of adiabatic pumping via topologically protected boundary states
[136] ; (b) illustration of the 2D array of waveguides with
z-dependent spacing
[137] Fig. 14. Systems with parameter dependency. (a) 1D photonic crystal with each unit cell including four layers where the thickness of each layer depends on parameters
p and
q[140]; (b) the design of photonic crystal with a PT-symmetric seven-layer unit cell,
n and
κ represent real and imaginary part of refractive index of each layer, respectively
[142]; (c) schematic of the unit