Pariksha SaathiJNCASR's silicon chip lets terahertz waves cross an engineered barrier with little loss while carrying data at up to 100 Gbit/s; could enable future 6G networks
Researchers at the Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), an autonomous institute of the Department of Science and Technology (DST), have demonstrated a silicon chip that lets terahertz waves pass through an engineered barrier with little loss while carrying data at up to 100 gigabits per second (Gbit/s), the Ministry of Science and Technology said on 4 November 2026; according to the release, the result points to compact terahertz circuits for future sixth-generation (6G) communication technologies. 6G wireless networks are expected to use terahertz frequencies, which lie between microwaves and infrared light and offer wide bandwidth, but guiding these waves through compact circuits is challenging because bends, junctions and abrupt changes in a waveguide can scatter or reflect part of the signal. Using topological photonics, the team designed a silicon photonic crystal - triangular holes arranged in a silicon slab in a pattern that mimics the honeycomb lattice of graphene - and created a barrier by changing the sizes of the triangular holes over a short section of the waveguide. A single barrier added only about 1–2% loss and two barriers in sequence about 2–3%, whereas in a conventional, non-topological waveguide a comparable barrier markedly reduces transmission; transmission stayed close to its barrier-free level as long as the barrier strength stayed below a characteristic coupling strength of the crystal. The concept was tested in three devices fabricated on high-resistivity silicon, a material compatible with established semiconductor manufacturing: one with two barriers in sequence, one with an omega-shaped route containing four sharp bends and a central barrier, and a power splitter with a barrier in one of its two branches. Measurements across 310–360 GHz agreed closely with simulations. In high-speed data tests the double-barrier and omega-shaped devices carried 48 and 60 Gbit/s respectively, and the splitter supported 100 Gbit/s using QAM-32 modulation. The study, published in the journal Advanced Materials, was led by Dr Abhishek Kumar, Assistant Professor at JNCASR, who heads its Meta Optics Laboratory (MetoLab), with Samina Mulla and Sangram Kumar Sadhu of JNCASR as joint first authors; the release's figure captions call the effect photonic Klein tunnelling. The team next plans to tune the barriers electrically, thermally or mechanically, which could allow a device to redirect signals between paths on demand.
Drafted with AI assistance from the official PIB release linked above and checked against it by a second AI pass. Not line-edited by a human.
Learning context
On 3 July 2023 the Department of Telecommunications (DoT) announced the formation of the Bharat 6G Alliance (B6GA), a collaborative platform of public and private companies, academia, research institutions and standards development organisations; the announcement was made by Union Minister Ashwini Vaishnaw. The alliance's primary objective is to understand the business and societal needs of 6G beyond technology requirements, foster consensus on these needs and promote high-impact open research and development (R&D) initiatives; it also seeks to accelerate standards-related patent creation within the country and to contribute actively to international standardisation organisations such as 3GPP and ITU. The same day, with a grant of Rs 240.51 crore under the Telecom Technology Development Fund (TTDF), two agreements were signed for projects: a 6G THz (terahertz) Testbed with Orbital Angular Momentum (OAM) and Multiplexing, through a consortium of SAMEER, IIT Madras, IIT Guwahati and IIT Patna, and an Advance Optical Communication Test Bed. The TTDF scheme was launched by DoT/USOF on 1 October 2022, and 5% of USOF's annual collections is to be available for it to fund research and development of technologies, products and services.
Check yourself: when was the Bharat 6G Alliance formed, and through which consortium was the 6G THz testbed funded under the TTDF to be built?
On 3 July 2023; a consortium of SAMEER, IIT Madras, IIT Guwahati and IIT Patna.
Revision task: from this release, note the institute and its parent department, what the chip does, the lattice its photonic crystal mimics, the loss added by one and by two barriers, the three test devices, the frequency range measured, the data rates achieved, the modulation used, the journal and who led the study; from the note, the date and objectives of the Bharat 6G Alliance, the TTDF grant and its two projects, and when the TTDF scheme was launched. Remember that the release says the chip could enable 6G networks, not that it already does.
Test yourself
Researchers at which institute demonstrated a silicon chip that lets terahertz waves cross an engineered barrier while carrying data at up to 100 Gbit/s, a result the Ministry of Science and Technology said on 4 November 2026 could enable future 6G networks?
Show the answer
Answer: Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR)
The Ministry of Science and Technology said researchers at JNCASR, an autonomous institute of the DST, used topological photonics to design a silicon photonic crystal mimicking the honeycomb lattice of graphene; a single engineered barrier added only about 1–2% loss, and a power splitter supported 100 Gbit/s. The study, led by Dr Abhishek Kumar, was published in the journal Advanced Materials.
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