TY - JOUR
T1 - An ultrastrongly coupled single terahertz meta-atom
AU - Rajabali, Shima
AU - Markmann, Sergej
AU - Jöchl, Elsa
AU - Beck, Mattias
AU - Lehner, Christian A.
AU - Wegscheider, Werner
AU - Faist, Jérôme
AU - Scalari, Giacomo
PY - 2022
Y1 - 2022
N2 - Free-space coupling to subwavelength individual optical elements is a central theme in quantum optics, as it allows the control over individual quantum systems. Here we show that, by combining an asymmetric immersion lens setup and a complementary resonating metasurface we are able to perform terahertz time-domain spectroscopy of an individual, strongly subwavelength meta-atom. We unravel the linewidth dependence as a function of the meta-atom number indicating quenching of the superradiant coupling. On these grounds, we investigate ultrastrongly coupled Landau polaritons at the single resonator level, measuring a normalized coupling ratio Ω/ω=0.6. Similar measurements on a lower density two dimensional electron gas yield a coupling ratio Ω/ω=0.33 with a cooperativity C = 94. Our findings pave the way towards the control of ultrastrong light-matter interaction at the single electron/ resonator level. The proposed technique is way more general and can be useful to characterize the complex conductivity of micron-sized samples in the terahertz domain.
AB - Free-space coupling to subwavelength individual optical elements is a central theme in quantum optics, as it allows the control over individual quantum systems. Here we show that, by combining an asymmetric immersion lens setup and a complementary resonating metasurface we are able to perform terahertz time-domain spectroscopy of an individual, strongly subwavelength meta-atom. We unravel the linewidth dependence as a function of the meta-atom number indicating quenching of the superradiant coupling. On these grounds, we investigate ultrastrongly coupled Landau polaritons at the single resonator level, measuring a normalized coupling ratio Ω/ω=0.6. Similar measurements on a lower density two dimensional electron gas yield a coupling ratio Ω/ω=0.33 with a cooperativity C = 94. Our findings pave the way towards the control of ultrastrong light-matter interaction at the single electron/ resonator level. The proposed technique is way more general and can be useful to characterize the complex conductivity of micron-sized samples in the terahertz domain.
UR - http://www.scopus.com/inward/record.url?scp=85129524972&partnerID=8YFLogxK
U2 - 10.1038/s41467-022-29974-2
DO - 10.1038/s41467-022-29974-2
M3 - Article
C2 - 35534466
AN - SCOPUS:85129524972
SN - 2041-1723
VL - 13
JO - Nature Communications
JF - Nature Communications
IS - 1
M1 - 2528
ER -