All publications

106. J. Christensen, M. Haberman, A. Srivastava, G. Huang, and G. Shmuel
“Perspective on Non-Hermitian elastodynamics”
Submitted (2024).

105. Q. Ji, B. Li, C. Wang, J. Christensen, and M. Kadic
“Superconductivity and semimetal insulator transition in strained mono- and bi-layers of graphene”
Submitted (2024).

104. J. Shi, H. Chu, A. Merkel, C. Liu, J. Christensen, X. Liu, and Y. Lai
“Parity metamaterials and dynamic acoustic camouflages”
Submitted (2023).

103. Y. Wang, Y. Ding, B. Liang, J. Cheng, and J. Christensen
“Experimental demonstration of a sonic valley-Chern insulator”
Submitted (2023).

102. W. Wang, J. Hu, J. Liu, Y. Tan, J. Yang, B. Liang, J. Christensen, and J. Cheng
“Single-sensor and real-time ultrasonic imaging using an AI-driven disordered metasurface”
Submitted (2023). [preprint]

101. B. Hu, Z. Zhang, Y. Liu, D. Liao, Y. Zhu, H. Zhang, Y. Cheng, X. Liu, and J. Christensen
“Engineering higher-order topological confinement via acoustic non-Hermitian textures”
Advanced Materials To be issued, 2406567 (2024). [pdf]

100. D. Liao, J. Zhang, S. Wang, Z. Zhang, A. Cortijo, M. A. H. Vozmediano, F. Guinea, Y. Cheng, X. Liu, and J. Christensen
“Visualizing the topological pentagon states of a giant C₅₄₀ metamaterial”
Nature Communications 15, 9644 (2024). [pdf]

99. R. Pernas-Salomón, P. Gao, Z. Zhang, and J. Christensen
“Investigating topological valley disclinations using multiple scattering and null-field theories”
Communications Materials 5, 169 (2024). [pdf]

98. L. Zhang, Y. Ge, Y.-J. Guan, F. Chen, N. Han, Q. Chen, Y. Pan, D. Jia, S.-Q. Yuan, H.-X. Sun, J. Christensen, H. Chen, and Y. Yang
“Nonreciprocal acoustic devices with asymmetric Peierls phases”
Physical Review Letters 133, 136601 (2024). [pdf]

97. L. Zheng and J. Christensen
“Three-dimensional quantum Hall effect in acoustic crystals”
Science Bulletin 123 242201 (2024). [pdf]

96. J. Zheng , L. Zheng , S. Yu , S. Yang , L. Liu , X. Sun, Y.-F. Chen, M.-H. Lu, and J. Christensen
“Focusing micromechanical polaritons in topologically nontrivial hyperbolic metasurfaces”
Advanced Materials 36, 2311599 (2024). [pdf]
Cover story [👌]

95. Z. Yue, Z. Zhang, Y. Cheng, X. Liu, and J. Christensen
“Acoustic real second-order nodal-loop semimetal and non-Hermitian modulation”
Applied Physics Letters 123, 242201 (2023). [pdf]

94. H.-X. Li, J.-J. Liu, Z.-X. Chen, K. Wu, B. Liang, J.-C. Cheng, and J. Christensen
“Superwavelength Self-Healing of Spoof Surface Sonic Airy-Talbot Waves”
Nature Communications 14, 7633 (2023). [pdf]

93. C.-X. Zhang, A. Chen, W. Hu, J. Yang, B. Liang, J. Christensen, and J.-C. Cheng
“Topological heterostructures for spectrally nearly constant intensity enhancements of audio sound and ultrasonics”
Physical Review Applied. 20, 024040 (2023). [pdf]

92. D. Liao, Y. Liu, Z. Zhang, X. Liu, C. Ying, and J. Christensen
“Topological acoustic rainbow trapping at deep-subwavelength corners”
Science Bulletin 68, 1744 (2023). [pdf]

91. B. Hu, Z. Zhang, Z. Yue, D. Liao, Y. Liu, H. Zhang, Y. Cheng, X. Liu, and J. Christensen
“Anti-parity-time symmetry in a Su-Schrieffer-Heeger sonic lattice”
Physical Review Letters 131, 066601 (2023). [pdf]
Editors’ suggestion, Cover story [👌]

90. X. Zhang, F. Zangeneh-Nejad, Z.-G. Chen, M.-H. Lu, and J. Christensen
“A Second Wave of Topological Phenomena in Photonics and Acoustics”
Nature 618, 687 (2023). [pdf]

89. D. Tan, M. Willatzen, and J. Christensen
“Structuring thermal transport in pristine graphene with h-BN nanorings”
J. Phys. Chem. Solids 180, 111414 (2023). [pdf]

88. A. O. Krushynska, …J. Christensen et al.
“Emerging topics in nanophononics, elastic, acoustic and mechanical metamaterials: An overview”
Nanophotonics 12, 659 (2023). [pdf]

87. J. Feilhauer, M. Zelent, Z. Zhang, J. Christensen, and M. Mruczkiewicz
“Unidirectional spin-wave edge modes in magnonic crystal”
APL Materials 11, 021104 (2023). [pdf]

86. D. Karlicić, M. Cajić, S. Paunović, A. Obradović, S. Adhikari, and J. Christensen
“Non-reciprocal wave propagation in time-modulated elastic lattices with inerters”
Applied Mathematical Modelling 117, 316 (2023). [pdf]

85. M. Cajić, D. Karlicić, J. Christensen, and S. Adhikari
“Tunable topological interface states in one-dimensional inerter-based locally resonant lattices with damping”
Journal of Sound and Vibration 542, 117326 (2023). [pdf]

84. J. Shi, C. Liu, C. Guo, H. Chu, X. Liu, J. Christensen, and Y. Lai
“Broadband acoustic metaveils for configurable camouflage”
Physical Review Applied 18, 064064 (2022). [pdf]

83. M. Rosendo-Lopez, Z. Zhang, D. Torrent, and J. Christensen
“Theory of holey twistsonic media”
Communications Materials 3, 99 (2022). [pdf]

82. R. Pernas-Salomón, L. Zheng, Z. Zhang, P. Gao, X. Liu, C. Ying, and J. Christensen
“Theory of non-Hermitian topological whispering gallery”
NPJ Computational Materials 8, 241 (2022). [pdf]

81. P. Gao, Y. Qu, and J. Christensen
“Non-Hermitian elastodynamics in gyro-odd continuum media”
Communications Materials 3, 74 (2022). [pdf]

80. Z. Zhang, P. Gao, W. Liu, Z. Yue, Y. Cheng, X. Liu, and J. Christensen
“Structured sonic tube with carbon nanotube-like topological edge states”
Nature Communications 13, 5096 (2022). [pdf]

79. Y. Jia, Y. Liu, B. Hu, W. Xiong, Y. Bai, Y. Cheng, D. Wu, X. Liu, and J. Christensen
“Orbital angular momentum multiplexing in space-time thermoacoustic metasurfaces”
Advanced Materials 34, 2202026 (2022). [pdf]
Cover story [👌]

78. J. Liu, Z. Li, Y. Ding, A. Chen, B. Liang, J. Yang, J.-C. Cheng, and J. Christensen
“Twisting linear to orbital angular momentum in an ultrasonic motor”
Advanced Materials 34, 2201575 (2022). [pdf]
Cover story [👌]

77. M Malléjac, T Cavalieri, V Romero-García, A Merkel, D Torrent, J. Christensen, J. Li, and J.-P. Groby
“Non-locality of the Willis coupling in fluid laminates”
Wave Motion 110, 102892 (2022). [pdf]

76. W. Xiong, P. Gao, Z. Zhang, Z. Yue, H. Zhang, Y. Cheng, Y. Liu, and J. Christensen
“Demultiplexing sound in stacked valley-Hall topological insulators”
Physical Review B 104, 224108 (2021). [pdf]

75. C. Oliver, G. Poignand, M. Mallejac, V. Romero-Garcia, G. Penelt, A. Merkel, D. Torrent, J. Li, J. Christensen, and J.-P. Groby
“Nonreciprocal and even Willis couplings in periodic thermoacoustic amplifiers”
Physical Review B 104, 184109 (2021). [pdf]

74. L. Zheng and J. Christensen
“Dirac hierarchy in acoustic topological insulators”
Physical Review Letters 127, 156401 (2021). [pdf]

73. B. Hu, Z. Zhang, H. Zhang, L. Zheng, W. Xiong, Z. Yue, X. Wang, J. Xu, Y. Cheng, X. Liu, and J. Christensen
“Non-Hermitian topological whispering gallery”
Nature 597, 655 (2021). [pdf]

72. C. Liu, W. Zhao, J. Shi, X. Zhou, C. Ma, R. Peng, M. Wang, Z. H. Hang, J. Christensen, N. X. Fang, and Y. Lai
“A three-dimensional soundproof acoustic metacage”
Physical Review Letters 127, 084301 (2021). [pdf]
Editors’ suggestion.

71. M. Cajić, J. Christensen, and S. Adhikari
“Tuning of topological interface modes in an elastic beam array system with inerters”
Int. J. Mech. Sci. 205, 106573 (2021). [pdf]

70. J. Zhang, W. Rui, C. Ma, Y. Cheng, X. Liu, and J. Christensen
“Remote Whispering Metamaterial: Non-radiative transceiving of ultra-weak sound”
Nature Communications 12, 3670 (2021). [pdf]

69. C.-W. Chen, R. Chaunsali, J. Christensen, G. Theocharis, and J. Yang
“Corner states in mechanical second-order topological insulators”
Communications Materials 2, 69 (2021). [pdf]

68. P. Gao and J. Christensen
“Topological vortices for sound and light”
Nature Nanotechnology 16, 487 (2021). [pdf]

67. M. Mallejac, A. Merkel, J. Sanchez-Dehesa, J. Christensen, V. Tournat, J.-P. Groby, and V. Romero-Garcia
“Experimental evidence of a hiding zone in a Density-Near-Zero Acoustic Metamaterial”
Journal of Applied Physics 129, 145101 (2021). [pdf]

66. L. Zheng and J. Christensen
“Topological radiation engineering in hyperbolic sonic semimetals”
Physical Review B 103, 064307 (2021). [pdf]

65. L. Zheng, X. Zhang, M.-H. Lu, Y.-F. Chen, and J. Christensen
“Knitting topological bands in artificial sonic semimetals”
Materials Today Physics 16, 100299 (2021). [pdf]

64. S.-Y. Yu, J.-Q. Wang, X.-C. Sun, F.-K. Liu, C. He, H.-H. Xu, M.-H. Lu, J. Christensen, X.-P. Liu, and Y.-F. Chen
“Slow surface acoustic waves via lattice optimization of a phononic crystal on a chip”
Physical Review Applied 14, 064008 (2020). [pdf]

63. M. Rosendo-Lopez, F. Peñaranda, J. Christensen, and P. San-Jose
“Flat bands in magic-angle vibrating plates”
Physical Review Letters 125, 214301 (2020). [pdf]

62. P. Gao, M. Willatzen, and J. Christensen
“Anomalous topological edge states in non-Hermitian piezophononic media”
Physical Review Letters 125, 206402 (2020). [pdf]

61. P. Gao and J. Christensen
“Topological sound pumping of zero-dimensional bound states”
Advanced Quantum Technologies 3, 2000065 (2020). [pdf]
Cover story [👌]

60. M. Willatzen, P. Gao, J. Christensen, and Z. L. Wang
“Acoustic gain in solids due to piezoelectricity, flexoelectricity, and electrostriction”
Advanced Functional Materials 30, 2003503 (2020). [pdf]

59. Z. Zhang, B. Hu, F. Liu, Y. Cheng, X. Liu, and J. Christensen
“Pseudospin induced topological corner state at intersecting sonic lattices”
Physical Review B (Rapid Communication) 101, 220102 (2020). [pdf]

58. P. Gao, Z. Zhang, and J. Christensen
“Sonic valley-Chern insulators”
Physical Review B (Rapid Communication) 101, 020301 (2020). [pdf]

57. A. Merkel and J. Christensen
“Ultrasonic nodal chains in topological granular metamaterials”
Communications Physics 2, 154 (2019). [pdf]

56. P. Gao, D. Torrent, F. Cervera, P. San-Jose, J. Sanchez-Dehesa, and J. Christensen
“Majorana-like zero modes in Kekulé distorted sonic lattices”
Physical Review Letters 123, 196601 (2019). [pdf]
Cover story [👌]

55. C.-W. Chen, N. Lera, R. Chaunsali, D. Torrent, J. V. Alvarez, J. Yang, P. San-Jose, and J. Christensen
“Mechanical analogue of a Majorana bound state”
Advanced Materials 31, 1904386 (2019). [pdf]

54. M. Rosendo-Lopez, Z. Zhang, D. Torrent, and J. Christensen
“Multiple scattering theory of non-Hermitian sonic second-order topological insulators”
Communications Physics 2, 132 (2019). [pdf]

53. Z. Zhang, H. Long, C. Liu, C. Shao, Y. Cheng, X. Liu, and J. Christensen
“Deep-subwavelength holey acoustic second-order topological insualators”
Advanced Materials 31, 1904682 (2019). [pdf]
Cover story [👌]

52. M. Mallejac, A. Merkel, J. Sanchez-Dehesa, J. Christensen, V. Tournat, J.-P. Groby, and V. Romero-Garcia
“Zero-phase propagation in realistic plate-type acoustic metamaterials”
Applied Physics Letters 115, 134101 (2019). [pdf]
Selected as an APL Editor’s Pick [link]

51. H.-X. Li, M. Rosendo-Lopez, Y.-F. Zhu, X.-D. Fan, D. Torrent, B. Liang, J.-C. Chun, and J.Christensen
“Ultrathin acoustic parity-time symmetric metasurface cloak”
SPJ Research 2019, 8345683 (2019). [pdf]

50. Z. Zhang, Y. Gu, H. Long, Y. Cheng, X. Liu, and J. Christensen
“Subwavelength Acoustic Valley-Hall Topological Insulators Using Soda Cans Honeycomb Lattices”
SPJ Research 2019, 5385763 (2019). [pdf]

49. Z. Zhang, Y. Cheng, X. Liu, and J. Christensen
“Subwavelength multiple topological interface states in 1D labyrinthine acoustic metamaterials”
Physical Review B 99, 224104 (2019). [pdf]

48. Z. Zhang, M. Rosendo Lopez, Y. Cheng, X. Liu, and J. Christensen
“Non-Hermitian sonic second-order topological insulator”
Physical Review Letters 122, 195501 (2019). [pdf]

47. N. Lera, D. Torrent, P. San-Jose, J. Christensen, and J. V. Alvarez
“Valley Hall phases in Kagome lattices”
Physical Review B 99, 134102 (2019). [pdf]

46. B. Li, Z. Li, J. Christensen, and K. T. Tan
“Dual Dirac cones in elastic Lieb-like lattice metamaterials”
Applied Physics Letters 114, 081906 (2019). [pdf]

45. X. Zhang, M. Xiao, Y. Cheng, M.-H. Lu, and J. Christensen
“Topological Sound”
Communications Physics 1, 97 (2018). [pdf]

44. M. Rosendo-Lopez, A. Merkel, and J. Christensen
“PT symmetric sonic crystals: From asymmetric echoes to supersonic speeds”
EPL (Europhysics Letters) 124, 34001 (2018). [pdf]

43. A. Merkel, V. Romero-Garcia, J.-P. Groby, J. Li, and J. Christensen
“Unidirectional zero sonic reflection in passive PT-symmetric Willis media”
Physical Review B (Rapid Communication) 98, 201102 (2018). [pdf]

42. Z. Zhang, Y. Tian, Y. Wang, S. Gao, Y. Cheng, X. Liu, and J. Christensen
“Directional acoustic antennas based on valley-Hall topological insulators”
Advanced Materials 30, 1803229 (2018). [pdf]

41. M. Wang, L. Ye, J. Christensen, and Z. Liu
“Valley Physics in non-Hermitian artificial Acoustic Boron Nitride”
Physical Review Letters 120, 246601 (2018). [pdf]

40. B. Li, K. T. Tan, and J. Christensen
“Heat conduction tuning by hyperbranched nanophononic metamaterials”
Journal of Applied Physics 123, 205105 (2018). [pdf]

39. R. Alaee, B. Gurlek, J. Christensen, and M. Kadic
“Optical force rectifiers based on PT-symmetric metasurfaces”
Physical Review B 97, 195420 (2018). [pdf]

38. A. Merkel, M. Willatzen, and J. Christensen
“Dynamic nonreciprocity in loss-compensated piezo-phononic media”
Physical Review Applied 9, 034033 (2018). [pdf]

37. Z. Zhang, Y. Tian, Y. Cheng, Q. Wei, X. Liu, and J. Christensen
“Topological acoustic delay line”
Physical Review Applied 9, 034032 (2018). [pdf]

36. R. Alaee, J. Christensen, and M. Kadic
“Optical pulling and pushing forces in bilayer PT-symmetric structures”
Physical Review Applied 9, 014007 (2018). [pdf]

35. Z. Zhang, Y. Tian, Y. Cheng, X. Liu, and J. Christensen
“Experimental verification of acoustic pseudospin multipoles in a symmetry-broken snowflakelike topological insulator”
Physical Review B (Rapid Communication) 96, 241306 (2017). [pdf]
A figure of this article has been chosen as a PRB Kaleidoscope [image].

34. K. Bertoldi, V. Vitelli, J. Christensen, and M. van Hecke
“Flexible mechanical metamaterials”
Nature Reviews Materials 2, 17066 (2017). [pdf]
Cover story [👌]

33. C. David and J. Christensen
“Extraordinary transmission through nonlocal holey metal films”
Applied Physics Letters 110, 261110 (2017). [pdf]
Selected by Editor Shanhui Fan as an APL Editor’s Pick [link]

32. B. Li, K. T. Tan and J. Christensen
“Tailoring the thermal conductivity in nanophononic metamaterials”
Physical Review B 95, 144305 (2017). [pdf]

31. G. Ma, C. Fu, G. Wang, P. del Hougne, J. Christensen, Y. Lai and P. Sheng
“Polarization Bandgaps and Fluid-like Elasticity in Fully Solid Elastic Metamaterials”
Nature Communications 7, 13536 (2016). [pdf]

30. C. David, J. Christensen and N. A. Mortensen
“Spatial dispersion in 2D plasmonic crystals: Large blueshifts promoted by diffraction anomalies”
Physical Review B 94, 165410 (2016). [pdf]

29. J. Christensen
“Coalescence towards exceptional contours in synthetic phononic media”
EPL (Europhysics Letters) 114, 47007 (2016). [pdf]

28. J. Christensen. M. Willatzen. V. R. Velasco and M.-H. Lu
“Parity-time synthetic phononic media”
Physical Review Letters 116, 207601 (2016). [pdf]

27. S. A. Cummer, J. Christensen and A. Alu
“Controlling sound with acoustic metamaterials”
Nature Reviews Materials 1, 16001 (2016). [pdf]
Selected by the editor to be free during the APS March Meeting 2018.

26. W. Wang, B.-H. Li, N. A. Mortensen, and J. Christensen
“Localized surface plasmons in vibrating graphene nanodisks”
Nanoscale 8, 3809 (2016). [pdf]

25. Z. Liang, M. Willatzen, and J. Christensen
“Mechanical properties of laminate materials: From surface waves to Bloch oscillations”
Physical Review Applied 4, 044012 (2015). [pdf]

24. J. Christensen, M. Kadic, O. Kraft, and M. Wegener
“Vibrant times for mechanical metamaterials”
Prospective article in MRS Commun. 5, 453 (2015). [pdf]

23. J. Christensen and M. Willatzen
“Tunable broadband acoustic gain in piezoelectric semiconductors at ɛ-near-zero response”
Acta Acust. United Ac. 10, 986 (2015). [pdf]

22. J. Christensen, Z. Liang and M. Willatzen
“Minimal model for spoof acoustoelastic surface states”
Special Topic: Selected Articles from Phononics 2013, Phononic Metamaterials, AIP Advances 4, 124301 (2014). [pdf]

21. J. Christensen, N. A. Mortensen and M. Willatzen
“Modelling the acoustical response of lossy lamella-crystals”
Journal of Applied Physics 116, 163508 (2014). [pdf]

20. J. Christensen and M. Willatzen
“Acoustic wave propagation and stochastic effects in metamaterial absorbers”
Applied Physics Letters 105, 043508 (2014). [pdf]

19. V.M. Garcia-Chocano, J. Christensen and J. Sánchez-Dehesa
“Negative refraction and energy funneling by hyperbolic materials: An experimental demonstration in acoustics”
Physical Review Letters 112, 144301 (2014). [pdf]

18. J. Christensen, V. Romero-García, R. Picó, A. Cebrecos, F.J. García de Abajo, N.A. Mortensen, M. Willatzen and V.J. Sánchez-Morcillo
“Extraordinary absorption of sound in porous lamella-crystals”
Scientific Reports 4, 4674 (2014). [pdf]

17. M. Willatzen, and J. Christensen
“Acoustic gain in piezoelectric semiconductors at ɛ-near-zero response”
Physical Review B (Rapid Communication) 89, 041201 (2014). [pdf]

16. J. Christensen, Z. Liang, and M. Willatzen
“Metadevices for the confinement of sound and broadband double-negativity behavior”
Physical Review B (Rapid Communication) 88, 100301 (2013). [pdf]
A figure of this article has been chosen as a PRB Kaleidoscope [image].

15. C. David, N.A. Mortensen, and J. Christensen
“Perfect imaging, epsilon-near zero phenomena and waveguiding in the scope of nonlocal effects”
Scientific Reports 3, 2526 (2013). [pdf]

14. Z. Liang, M. Willatzen, Jensen Li and J. Christensen
“Tunable acoustic double negativity metamaterial”
Scientific Reports 2, 859 (2012). [pdf]

13. J. Christensen and F. J. Garcia de Abajo
“Negative refraction and backward waves in layered acoustic metamaterials”
Physical Review B 86, 024301 (2012). [pdf]
This article has been selected by the editors as an “Editor’s choice”.

12. J. Christensen and F. J. Garcia de Abajo
“Anisotropic metamaterials for full control of acoustic waves”
Physical Review Letters 108, 124301 (2012). [pdf]

11. J. Christensen and M. Willatzen
“Flow-induced resonance shift in sonic slit array metamaterials”
Physical Review B 85, 094304 (2012). [pdf]

10. J. Christensen, A. Manjavacas, S. Thongrattanasiri, F. H. L. Koppens and F. J. Garcia de Abajo
“Graphene plasmon waveguiding and hybridization in individual and paired nanoribbons”
ACS Nano 6, 432 (2012). [pdf]

9. J. Zhu*, J. Christensen*, J. Jung, L. Martin-Moreno, X. Yin, L. Fok, F. J. Garcia-Vidal and Xiang Zhang
“A Holey structured metamaterial for acoustic deep subwavelength imaging”
Nature Physics 7, 52 (2011). [pdf] *These authors contributed equally.

8. J. Christensen and F. J. Garcia de Abajo
“Acoustic field enhancement and subwavelength imaging by coupling to slab waveguidemodes”
Applied Physics Letters 97, 164103 (2010). [pdf]

7. J. Christensen and F. J. Garcia de Abajo
“Slow plasmonic slab waveguide as a superlens for visible light”
Physical Review B (Rapid Communication) 82, 161103 (2010). [pdf]

6. J. Christensen, L. Martin-Moreno and F. J. Garcia-Vidal
“All-angle blockage of sound by an acoustic metamaterial”
Applied Physics Letters 97, 134106 (2010). [pdf]

5. J. Christensen, Martin-Moreno and F. J. Garcia-Vidal
“Collimation of horizontally polarized shear waves by means of ridge grating supported Love modes”
Applied Physics Letters 96, 233505 (2010). [pdf]

4. J. Christensen, Martin-Moreno and F. J. Garcia-Vidal
“Enhanced acoustical transmission and beaming effect through a single aperture”
Physical Review B 81, 174104 (2010). [pdf]

3. J. Christensen, P. A. Huidobro, Martin-Moreno and F. J. Garcia-Vidal
“Confining and slowing airborne sound with a corrugated metawire”
Applied Physics Letters 93, 083502 (2008). [pdf]

2. J. Christensen, Martin-Moreno and F. J. Garcia-Vidal,
“Theory of resonant acoustic transmission through subwavelength apertures”
Physical Review Letters 101, 014301 (2008). [pdf]

1. J. Christensen, A.I. Fernandez-Dominguez, F. de Leon-Perez, L. Martin-Moreno and F. J. Garcia-Vidal
“Collimation of sound assisted by acoustic surface waves”
Nature Physics 3, 851 (2007). [pdf]
Among the research highlights in Nature 450, 4 (2007). [pdf]