Lumped-element device for quantum information processing systems

A method of forming a lumped-element device in a quantum information processing circuit, the method comprising:

• receiving a dielectric substrate;
• forming a first capacitor pad on a surface of the dielectric substrate, the first capacitor pad being capacitively coupled to a second capacitor pad, the first capacitor pad having an outer boundary and an inner boundary, the inner boundary defining an interior clearance area in the first capacitor pad;
• forming an inductive transmission line on the dielectric substrate in the interior clearance area in the first capacitor pad;
• wherein forming the lumped-element device comprises forming a microwave resonator device having a resonance frequency in the range of two hundred (200) MHz to twenty (20) GHz, and the largest spatial dimension of the lumped-element device is less than one-tenth of a guided wavelength at the lowest-mode resonance frequency of the lumped-element device.

A quantum information processing circuit comprising:

• a qubit device;
• and
• a resonator device coupled to the qubit device, the resonator device comprising:
• a first capacitor pad on a dielectric substrate, the first capacitor pad being capacitively coupled to a second capacitor pad, the first capacitor pad having an outer boundary and an inner boundary, the inner boundary defining an interior clearance area in the first capacitor pad;
• and
• an inductive transmission line on the dielectric substrate in the interior clearance area in the first capacitor pad;
• wherein the resonator device comprises a microwave resonator device having a resonance frequency in the range of two hundred (200) MHz to twenty (20) GHz, and the largest spatial dimension of the resonator device is less than one-tenth of a guided wavelength at the lowest-mode resonance frequency of the resonator device.

A quantum information processing circuit comprising:

• a dielectric substrate;
• a lumped-element device on the dielectric substrate, the lumped-element device comprising:
• a first capacitor pad on the dielectric substrate, the first capacitor pad being capacitively coupled to a second capacitor pad, the first capacitor pad having an outer boundary and an inner boundary, the inner boundary defining an interior clearance area in the first capacitor pad;
• and
• an inductive transmission line on the dielectric substrate in the interior clearance area in the first capacitor pad;
• and
• a ground conductor, wherein the second capacitor pad resides in an interior clearance area of the ground conductor, and the first capacitor pad resides in an interior clearance area of the second capacitor pad.

A quantum information processing circuit comprising:

• a dielectric substrate;
• a lumped-element device on the dielectric substrate, the lumped-element device comprising:
• a first capacitor pad on the dielectric substrate, the first capacitor pad being capacitively coupled to a second capacitor pad, the first capacitor pad having an outer boundary and an inner boundary, the inner boundary defining an interior clearance area in the first capacitor pad;
• and
• an inductive transmission line on the dielectric substrate in the interior clearance area in the first capacitor pad;
• wherein the second capacitor pad has an outer boundary and an inner boundary, the inner boundary of the second capacitor pad defines an interior clearance area in the second capacitor pad, and the first capacitor pad resides in the interior clearance area in the second capacitor pad.